diff --git a/changelog/6404.trivial.rst b/changelog/6404.trivial.rst
new file mode 100644
index 000000000..5a60d01a4
--- /dev/null
+++ b/changelog/6404.trivial.rst
@@ -0,0 +1 @@
+Removed unused ``_pytest.code.Source.isparseable`` function.
diff --git a/src/_pytest/_code/source.py b/src/_pytest/_code/source.py
index d7cef683d..341462792 100644
--- a/src/_pytest/_code/source.py
+++ b/src/_pytest/_code/source.py
@@ -136,26 +136,6 @@ class Source:
         newsource.lines[:] = deindent(self.lines)
         return newsource
 
-    def isparseable(self, deindent: bool = True) -> bool:
-        """ return True if source is parseable, heuristically
-            deindenting it by default.
-        """
-        from parser import suite as syntax_checker
-
-        if deindent:
-            source = str(self.deindent())
-        else:
-            source = str(self)
-        try:
-            # compile(source+'\n', "x", "exec")
-            syntax_checker(source + "\n")
-        except KeyboardInterrupt:
-            raise
-        except Exception:
-            return False
-        else:
-            return True
-
     def __str__(self) -> str:
         return "\n".join(self.lines)
 
diff --git a/testing/code/test_source.py b/testing/code/test_source.py
index 1390d8b0a..511626fa0 100644
--- a/testing/code/test_source.py
+++ b/testing/code/test_source.py
@@ -121,15 +121,6 @@ def test_syntaxerror_rerepresentation() -> None:
     assert ex.value.text == "xyz xyz\n"
 
 
-def test_isparseable() -> None:
-    assert Source("hello").isparseable()
-    assert Source("if 1:\n  pass").isparseable()
-    assert Source(" \nif 1:\n  pass").isparseable()
-    assert not Source("if 1:\n").isparseable()
-    assert not Source(" \nif 1:\npass").isparseable()
-    assert not Source(chr(0)).isparseable()
-
-
 class TestAccesses:
     def setup_class(self) -> None:
         self.source = Source(
@@ -143,7 +134,6 @@ class TestAccesses:
 
     def test_getrange(self) -> None:
         x = self.source[0:2]
-        assert x.isparseable()
         assert len(x.lines) == 2
         assert str(x) == "def f(x):\n    pass"