diff --git a/Lib/tarfile.py b/Lib/tarfile.py
--- a/Lib/tarfile.py
+++ b/Lib/tarfile.py
@@ -417,28 +417,34 @@
         self.pos      = 0L
         self.closed   = False
 
-        if comptype == "gz":
-            try:
-                import zlib
-            except ImportError:
-                raise CompressionError("zlib module is not available")
-            self.zlib = zlib
-            self.crc = zlib.crc32("") & 0xffffffffL
-            if mode == "r":
-                self._init_read_gz()
-            else:
-                self._init_write_gz()
+        try:
+            if comptype == "gz":
+                try:
+                    import zlib
+                except ImportError:
+                    raise CompressionError("zlib module is not available")
+                self.zlib = zlib
+                self.crc = zlib.crc32("") & 0xffffffffL
+                if mode == "r":
+                    self._init_read_gz()
+                else:
+                    self._init_write_gz()
 
-        if comptype == "bz2":
-            try:
-                import bz2
-            except ImportError:
-                raise CompressionError("bz2 module is not available")
-            if mode == "r":
-                self.dbuf = ""
-                self.cmp = bz2.BZ2Decompressor()
-            else:
-                self.cmp = bz2.BZ2Compressor()
+            elif comptype == "bz2":
+                try:
+                    import bz2
+                except ImportError:
+                    raise CompressionError("bz2 module is not available")
+                if mode == "r":
+                    self.dbuf = ""
+                    self.cmp = bz2.BZ2Decompressor()
+                else:
+                    self.cmp = bz2.BZ2Compressor()
+        except:
+            if not self._extfileobj:
+                self.fileobj.close()
+            self.closed = True
+            raise
 
     def __del__(self):
         if hasattr(self, "closed") and not self.closed:
@@ -1685,9 +1691,12 @@
             if filemode not in ("r", "w"):
                 raise ValueError("mode must be 'r' or 'w'")
 
-            t = cls(name, filemode,
-                    _Stream(name, filemode, comptype, fileobj, bufsize),
-                    **kwargs)
+            stream = _Stream(name, filemode, comptype, fileobj, bufsize)
+            try:
+                t = cls(name, filemode, stream, **kwargs)
+            except:
+                stream.close()
+                raise
             t._extfileobj = False
             return t
 
@@ -1718,17 +1727,23 @@
         except (ImportError, AttributeError):
             raise CompressionError("gzip module is not available")
 
-        if fileobj is None:
-            fileobj = bltn_open(name, mode + "b")
+        try:
+            fileobj = gzip.GzipFile(name, mode, compresslevel, fileobj)
+        except OSError:
+            if fileobj is not None and mode == 'r':
+                raise ReadError("not a gzip file")
+            raise
 
         try:
-            t = cls.taropen(name, mode,
-                gzip.GzipFile(name, mode, compresslevel, fileobj),
-                **kwargs)
+            t = cls.taropen(name, mode, fileobj, **kwargs)
         except IOError:
+            fileobj.close()
             if mode == 'r':
                 raise ReadError("not a gzip file")
             raise
+        except:
+            fileobj.close()
+            raise
         t._extfileobj = False
         return t
 
@@ -1753,9 +1768,13 @@
         try:
             t = cls.taropen(name, mode, fileobj, **kwargs)
         except (IOError, EOFError):
+            fileobj.close()
             if mode == 'r':
                 raise ReadError("not a bzip2 file")
             raise
+        except:
+            fileobj.close()
+            raise
         t._extfileobj = False
         return t