diff --git a/python/src/com/jetbrains/python/packaging/conda/CondaPackageManagerEngine.kt b/python/src/com/jetbrains/python/packaging/conda/CondaPackageManagerEngine.kt
index 61c65a9b4ce0..b21b987bf94f 100644
--- a/python/src/com/jetbrains/python/packaging/conda/CondaPackageManagerEngine.kt
+++ b/python/src/com/jetbrains/python/packaging/conda/CondaPackageManagerEngine.kt
@@ -35,7 +35,7 @@ internal class CondaPackageManagerEngine(private val sdk: Sdk) : PythonPackageMa
   }
 
   override suspend fun installPackageCommand(installRequest: PythonPackageInstallRequest, options: List<String>): PyResult<Unit> {
-    val installationArgs = installRequest.buildInstallationArguments().getOr { return it }
+    val installationArgs = installRequest.buildCondaInstallationArguments().getOr { return it }
     val env = getEnvData()
     return CondaExecutor.installPackages(sdk.getCondaBinToExecute(), env.envIdentity, installationArgs, options)
   }
@@ -61,20 +61,18 @@ internal class CondaPackageManagerEngine(private val sdk: Sdk) : PythonPackageMa
 
 
   private fun getEnvData(): PyCondaEnv = (sdk.pySdkAdditionalData.flavorAndData.data as PyCondaFlavorData).env
+}
 
-  private fun PythonPackageInstallRequest.buildInstallationArguments(): PyResult<List<String>> = when (this) {
-    is PythonPackageInstallRequest.ByLocation -> PyResult.localizedError(PyBundle.message("python.packaging.conda.does.not.support.location.uri"))
-    is PythonPackageInstallRequest.ByRepositoryPythonPackageSpecifications -> {
-      val condaSpecs = specifications.filter { it.repository is CondaPackageRepository }
-      val specs = condaSpecs.map { it.nameWithVersionSpec }
+internal fun PythonPackageInstallRequest.buildCondaInstallationArguments(): PyResult<List<String>> = when (this) {
+  is PythonPackageInstallRequest.ByLocation -> PyResult.localizedError(PyBundle.message("python.packaging.conda.does.not.support.location.uri"))
+  is PythonPackageInstallRequest.ByRepositoryPythonPackageSpecifications -> {
+    val condaSpecs = specifications.filter { it.repository is CondaPackageRepository }
+    val specs = condaSpecs.map { it.nameWithVersionSpec }
 
-      //https://docs.conda.io/projects/conda/en/latest/user-guide/concepts/pkg-specs.html#package-match-specifications
-      //When using the command line, put double quotes around any package version specification that
-      // contains the space character or any of the following characters: <, >, *, or |.
-      //Ido not know why we need put single prefix quota but it does not work in EEL with suffix quota
-      val quoted = specs.map { "\"$it" }
-
-      PyResult.success(quoted)
-    }
+    // Each spec is passed to conda as a single argv element (no shell), so it must not be quoted.
+    // conda's docs recommend double quotes only for shell command lines to protect characters like <, >, *, |.
+    // Wrapping the spec in a quote here glues a literal '"' onto the package name, which conda 26.x rejects
+    // with InvalidMatchSpec (PY-91412).
+    PyResult.success(specs)
   }
 }
\ No newline at end of file
diff --git a/python/testSrc/com/jetbrains/python/packaging/conda/CondaInstallationArgumentsTest.kt b/python/testSrc/com/jetbrains/python/packaging/conda/CondaInstallationArgumentsTest.kt
new file mode 100644
index 000000000000..f4baa1c7d19a
--- /dev/null
+++ b/python/testSrc/com/jetbrains/python/packaging/conda/CondaInstallationArgumentsTest.kt
@@ -0,0 +1,29 @@
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package com.jetbrains.python.packaging.conda
+
+import com.intellij.testFramework.junit5.TestApplication
+import com.jetbrains.python.getOrThrow
+import com.jetbrains.python.packaging.common.PythonRepositoryPackageSpecification
+import com.jetbrains.python.packaging.management.PythonPackageInstallRequest
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertTrue
+import org.junit.jupiter.api.Test
+
+@TestApplication
+class CondaInstallationArgumentsTest {
+  // PY-91412: specs are passed to conda as individual argv elements (no shell), so they must reach conda verbatim.
+  // A stray leading double-quote used to be glued onto every spec, which conda 26.x rejects with InvalidMatchSpec.
+  @Test
+  fun testCondaSpecsAreNotQuoted() {
+    val specs = listOf(
+      PythonRepositoryPackageSpecification(CondaPackageRepository, "seaborn"),
+      PythonRepositoryPackageSpecification(CondaPackageRepository, "seaborn", "0.13.2"),
+    )
+    val request = PythonPackageInstallRequest.ByRepositoryPythonPackageSpecifications(specs)
+
+    val args = request.buildCondaInstallationArguments().getOrThrow()
+
+    assertEquals(specs.map { it.nameWithVersionSpec }, args)
+    assertTrue(args.none { it.contains('"') }, "Conda specs must not contain quote characters: $args")
+  }
+}