diff --git a/python/src/com/jetbrains/python/psi/impl/PyFunctionBuilder.java b/python/src/com/jetbrains/python/psi/impl/PyFunctionBuilder.java
index 55955e0622b4..53dea09e4f5c 100644
--- a/python/src/com/jetbrains/python/psi/impl/PyFunctionBuilder.java
+++ b/python/src/com/jetbrains/python/psi/impl/PyFunctionBuilder.java
@@ -24,23 +24,34 @@ import com.intellij.util.ArrayUtil;
 import com.jetbrains.python.PyNames;
 import com.jetbrains.python.PythonFileType;
 import com.jetbrains.python.psi.*;
+
 import org.jetbrains.annotations.NotNull;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.regex.Pattern;
 
 /**
  * @author yole
  */
 public class PyFunctionBuilder {
+  private static final String COMMENTS_BOUNDARY = "\"\"\"";
+  private static final Pattern INDENT_REMOVE_PATTERN = Pattern.compile("^\\s+", Pattern.MULTILINE);
   private final String myName;
   private final List<String> myParameters = new ArrayList<String>();
   private final List<String> myStatements = new ArrayList<String>();
   private final List<String> myDecorators = new ArrayList<String>();
   private String myAnnotation = null;
+  private String[] myDocStringLines = null;
 
-  //TODO: Doc
+  /**
+   * Creates builder copying signature and doc from another one.
+   * @param source what to copy
+   * @param decoratorsToCopyIfExist list of decorator names to be copied to new function.
+   * @return builder configured by this function
+   */
   @NotNull
   public static PyFunctionBuilder copySignature(@NotNull final PyFunction source, @NotNull final String... decoratorsToCopyIfExist) {
     final String name = source.getName();
@@ -62,9 +73,26 @@ public class PyFunctionBuilder {
         }
       }
     }
+    final String docString = source.getDocStringValue();
+    if (docString != null) {
+      functionBuilder.docString(docString);
+    }
     return functionBuilder;
   }
 
+  /**
+   * Adds docstring to function. Provide doc with out of comment blocks.
+   * @param docString doc
+   */
+  public void docString(@NotNull final String docString) {
+    myDocStringLines = StringUtil.splitByLines(removeIndent(docString));
+  }
+
+  @NotNull
+  private String removeIndent(@NotNull final String string) {
+    return INDENT_REMOVE_PATTERN.matcher(string).replaceAll("");
+  }
+
   public PyFunctionBuilder(String name) {
     myName = name;
   }
@@ -118,6 +146,16 @@ public class PyFunctionBuilder {
     }
     builder.append(":");
     List<String> statements = myStatements.isEmpty() ? Collections.singletonList(PyNames.PASS) : myStatements;
+
+    if (myDocStringLines != null) {
+      final List<String> comments = new ArrayList<String>(myDocStringLines.length + 2);
+      comments.add(COMMENTS_BOUNDARY);
+      comments.addAll(Arrays.asList(myDocStringLines));
+      comments.add(COMMENTS_BOUNDARY);
+      statements = new ArrayList<String>(statements);
+      statements.addAll(0, comments);
+    }
+
     final CodeStyleSettings codeStyleSettings = CodeStyleSettingsManager.getInstance(project).getCurrentSettings();
     int indentSize = codeStyleSettings.getIndentOptions(PythonFileType.INSTANCE).INDENT_SIZE;
     String indent = StringUtil.repeatSymbol(' ', indentSize);
@@ -130,4 +168,11 @@ public class PyFunctionBuilder {
   public void decorate(String decoratorName) {
     myDecorators.add("@" + decoratorName);
   }
+
+  @NotNull
+  private static String getIndent(@NotNull final Project project) {
+    final CodeStyleSettings codeStyleSettings = CodeStyleSettingsManager.getInstance(project).getCurrentSettings();
+    final int indentSize = codeStyleSettings.getIndentOptions(PythonFileType.INSTANCE).INDENT_SIZE;
+    return StringUtil.repeatSymbol(' ', indentSize);
+  }
 }
diff --git a/python/testData/refactoring/extractsuperclass/moveAndMakeAbstract/dest_module.after.py b/python/testData/refactoring/extractsuperclass/moveAndMakeAbstract/dest_module.after.py
index 9b1670daef11..bbf726c919ae 100644
--- a/python/testData/refactoring/extractsuperclass/moveAndMakeAbstract/dest_module.after.py
+++ b/python/testData/refactoring/extractsuperclass/moveAndMakeAbstract/dest_module.after.py
@@ -7,4 +7,7 @@ class NewParent(object):
 
     @abstractmethod
     def foo_method(self):
+        """
+        Foo
+        """
         pass
\ No newline at end of file
diff --git a/python/testData/refactoring/extractsuperclass/moveAndMakeAbstract/source_module.after.py b/python/testData/refactoring/extractsuperclass/moveAndMakeAbstract/source_module.after.py
index 2da9618b43f0..6e71752a511d 100644
--- a/python/testData/refactoring/extractsuperclass/moveAndMakeAbstract/source_module.after.py
+++ b/python/testData/refactoring/extractsuperclass/moveAndMakeAbstract/source_module.after.py
@@ -3,4 +3,7 @@ from dest_module import NewParent
 
 class MyClass(NewParent):
     def foo_method(self):
+        """
+        Foo
+        """
         spam = "eggs"
\ No newline at end of file
diff --git a/python/testData/refactoring/extractsuperclass/moveAndMakeAbstract/source_module.py b/python/testData/refactoring/extractsuperclass/moveAndMakeAbstract/source_module.py
index ed2d3668c71e..f4a7c42a7df4 100644
--- a/python/testData/refactoring/extractsuperclass/moveAndMakeAbstract/source_module.py
+++ b/python/testData/refactoring/extractsuperclass/moveAndMakeAbstract/source_module.py
@@ -1,3 +1,6 @@
 class MyClass(object):
     def foo_method(self):
+        """
+        Foo
+        """
         spam = "eggs"
\ No newline at end of file
diff --git a/python/testData/refactoring/pullup/abstractMethodPy3AddMeta/Class.after.py b/python/testData/refactoring/pullup/abstractMethodPy3AddMeta/Class.after.py
index 91ab0b1c2b02..c0e75fa98646 100644
--- a/python/testData/refactoring/pullup/abstractMethodPy3AddMeta/Class.after.py
+++ b/python/testData/refactoring/pullup/abstractMethodPy3AddMeta/Class.after.py
@@ -1,6 +1,10 @@
 from SuperClass import Parent
 class Child(Parent):
     def my_method(self, foo):
+        """
+        Eats eggs
+        :param foo: eggs
+        """
         bar = foo
 
     @classmethod
diff --git a/python/testData/refactoring/pullup/abstractMethodPy3AddMeta/Class.py b/python/testData/refactoring/pullup/abstractMethodPy3AddMeta/Class.py
index 91ab0b1c2b02..c0e75fa98646 100644
--- a/python/testData/refactoring/pullup/abstractMethodPy3AddMeta/Class.py
+++ b/python/testData/refactoring/pullup/abstractMethodPy3AddMeta/Class.py
@@ -1,6 +1,10 @@
 from SuperClass import Parent
 class Child(Parent):
     def my_method(self, foo):
+        """
+        Eats eggs
+        :param foo: eggs
+        """
         bar = foo
 
     @classmethod
diff --git a/python/testData/refactoring/pullup/abstractMethodPy3AddMeta/SuperClass.after.py b/python/testData/refactoring/pullup/abstractMethodPy3AddMeta/SuperClass.after.py
index 8311ea6a630a..ded9ea669c57 100644
--- a/python/testData/refactoring/pullup/abstractMethodPy3AddMeta/SuperClass.after.py
+++ b/python/testData/refactoring/pullup/abstractMethodPy3AddMeta/SuperClass.after.py
@@ -4,6 +4,10 @@ from abc import object
 class Parent(object, metaclass=ABCMeta):
     @abstractmethod
     def my_method(self, foo):
+        """
+        Eats eggs
+        :param foo: eggs
+        """
         pass
 
     @classmethod