diff --git a/Lib/test/test_decimal.py b/Lib/test/test_decimal.py
index e5f7f64..5e69b64 100644
--- a/Lib/test/test_decimal.py
+++ b/Lib/test/test_decimal.py
@@ -615,6 +615,98 @@
             self.assertEqual(eval('Decimal(10)' + sym + 'E()'),
                              '10' + rop + 'str')
 
+class DecimalFormatTest(unittest.TestCase):
+    '''Unit tests for the format function.'''
+    def test_formatting(self):
+        # triples giving a format, a Decimal, and the expected result
+        test_values = [
+            ('e', '0E-15', '0e-15'),
+            ('e', '2.3E-15', '2.3e-15'),
+            ('e', '2.30E+2', '2.30e+2'), # preserve significant zeros
+            ('e', '2.30000E-15', '2.30000e-15'),
+            ('e', '1.23456789123456789e40', '1.23456789123456789e+40'),
+            ('e', '1.5', '1.5e+0'),
+            ('e', '0.15', '1.5e-1'),
+            ('e', '0.015', '1.5e-2'),
+            ('e', '0.0000000000015', '1.5e-12'),
+            ('e', '15.0', '1.50e+1'),
+            ('e', '-15', '-1.5e+1'),
+            ('e', '0', '0e+0'),
+            ('e', '0E1', '0e+1'),
+            ('e', '0.0', '0e-1'),
+            ('e', '0.00', '0e-2'),
+            ('.6e', '0E-15', '0.000000e-9'),
+            ('.6e', '0', '0.000000e+6'),
+            ('.6e', '9.999999', '9.999999e+0'),
+            ('.6e', '9.9999999', '1.000000e+1'),
+            ('.6e', '-1.23e5', '-1.230000e+5'),
+            ('.6e', '1.23456789e-3', '1.234568e-3'),
+            ('f', '0', '0'),
+            ('f', '0.0', '0.0'),
+            ('f', '0E-2', '0.00'),
+            ('f', '0.00E-8', '0.0000000000'),
+            ('f', '0E1', '0'), # loses exponent information
+            ('f', '3.2E1', '32'),
+            ('f', '3.2E2', '320'),
+            ('f', '3.20E2', '320'),
+            ('f', '3.200E2', '320.0'),
+            ('f', '3.2E-6', '0.0000032'),
+            ('.6f', '0E-15', '0.000000'), # all zeros treated equally
+            ('.6f', '0E1', '0.000000'),
+            ('.6f', '0', '0.000000'),
+            ('.0f', '0', '0'), # no decimal point
+            ('.0f', '0e-2', '0'),
+            ('.0f', '3.14159265', '3'),
+            ('.1f', '3.14159265', '3.1'),
+            ('.4f', '3.14159265', '3.1416'),
+            ('.6f', '3.14159265', '3.141593'),
+            ('.7f', '3.14159265', '3.1415926'), # round-half-even!
+            ('.8f', '3.14159265', '3.14159265'),
+            ('.9f', '3.14159265', '3.141592650'),
+
+            ('g', '0', '0'),
+            ('g', '0.0', '0.0'),
+            ('g', '0E1', '0e+1'),
+            ('G', '0E1', '0E+1'),
+            ('g', '0E-5', '0.00000'),
+            ('g', '0E-6', '0.000000'),
+            ('g', '0E-7', '0e-7'),
+            ('g', '-0E2', '-0e+2'),
+            ('.0g', '3.14159265', '3'),  # 0 sig fig -> 1 sig fig
+            ('.1g', '3.14159265', '3'),
+            ('.2g', '3.14159265', '3.1'),
+            ('.5g', '3.14159265', '3.1416'),
+            ('.7g', '3.14159265', '3.141593'),
+            ('.8g', '3.14159265', '3.1415926'), # round-half-even!
+            ('.9g', '3.14159265', '3.14159265'),
+            ('.10g', '3.14159265', '3.14159265'), # don't pad
+
+            ('%', '0E1', '0%'),
+            ('%', '0E0', '0%'),
+            ('%', '0E-1', '0%'),
+            ('%', '0E-2', '0%'),
+            ('%', '0E-3', '0.0%'),
+            ('%', '0E-4', '0.00%'),
+
+            ('.3%', '0', '0.000%'), # all zeros treated equally
+            ('.3%', '0E10', '0.000%'),
+            ('.3%', '0E-10', '0.000%'),
+            ('.3%', '2.34', '234.000%'),
+            ('.3%', '1.234567', '123.457%'),
+            ('.0%', '1.23', '123%'),
+
+            ('e', 'NaN', 'NaN'),
+            ('f', '-NaN123', '-NaN123'),
+            ('+g', 'NaN456', '+NaN456'),
+            ('.3e', 'Inf', 'Infinity'),
+            ('.16f', '-Inf', '-Infinity'),
+            ('.0g', '-sNaN', '-sNaN'),
+
+            ('', '1.00', '1.00'),
+            ]
+        for fmt, d, result in test_values:
+            self.assertEqual(format(Decimal(d), fmt), result)
+
 class DecimalArithmeticOperatorsTest(unittest.TestCase):
     '''Unit tests for all arithmetic operators, binary and unary.'''
 
@@ -1363,6 +1455,7 @@
             DecimalExplicitConstructionTest,
             DecimalImplicitConstructionTest,
             DecimalArithmeticOperatorsTest,
+            DecimalFormatTest,
             DecimalUseOfContextTest,
             DecimalUsabilityTest,
             DecimalPythonAPItests,