diff --git a/src/crypto/aes/asm_s390x.s b/src/crypto/aes/asm_s390x.s
new file mode 100644
index 0000000000..4a0720ca17
--- /dev/null
+++ b/src/crypto/aes/asm_s390x.s
@@ -0,0 +1,35 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "textflag.h"
+
+// func hasAsm() bool
+TEXT ·hasAsm(SB),NOSPLIT,$16-1
+	XOR	R0, R0          // set function code to 0 (query)
+	LA	mask-16(SP), R1 // 16-byte stack variable for mask
+	WORD	$0xB92E0024     // cipher message (KM)
+
+	// check if bits 18-20 (big endian) are set
+	MOVD	mask-16(SP), R2
+	MOVD	$(0x38<<40), R3
+	AND	R3, R2
+	CMPBNE	R2, R3, notfound
+	MOVB	$1, ret+0(FP)
+	RET
+notfound:
+	MOVB	$0, ret+0(FP)
+	RET
+
+// func cryptBlocks(function code, key, dst, src *byte, length int)
+TEXT ·cryptBlocks(SB),NOSPLIT,$0-40
+	MOVD	key+8(FP), R1
+	MOVD	dst+16(FP), R2
+	MOVD	src+24(FP), R4
+	MOVD	length+32(FP), R5
+	MOVD	function+0(FP), R0
+loop:
+	WORD	$0xB92E0024 // cipher message (KM)
+	BVS	loop        // branch back if interrupted
+	XOR	R0, R0
+	RET
diff --git a/src/crypto/aes/cipher_generic.go b/src/crypto/aes/cipher_generic.go
index c5e02fe79b..fc2c4c52cf 100644
--- a/src/crypto/aes/cipher_generic.go
+++ b/src/crypto/aes/cipher_generic.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !amd64
+// +build !amd64,!s390x
 
 package aes
 
diff --git a/src/crypto/aes/cipher_s390x.go b/src/crypto/aes/cipher_s390x.go
new file mode 100644
index 0000000000..dfb95d7d5d
--- /dev/null
+++ b/src/crypto/aes/cipher_s390x.go
@@ -0,0 +1,84 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package aes
+
+import (
+	"crypto/cipher"
+)
+
+type code int
+
+// Function codes for the cipher message family of instructions.
+const (
+	aes128 code = 18
+	aes192      = 19
+	aes256      = 20
+)
+
+type aesCipherAsm struct {
+	function code      // code for cipher message instruction
+	key      []byte    // key (128, 192 or 256 bytes)
+	storage  [256]byte // array backing key slice
+}
+
+// hasAsm reports whether the AES-128, AES-192 and AES-256
+// cipher message (KM) function codes are supported.
+// Note: this function call is expensive.
+func hasAsm() bool
+
+// cryptBlocks invokes the cipher message (KM) instruction with
+// the given function code. This is equivalent to AES in ECB
+// mode. The length must be a multiple of BlockSize (16).
+//go:noesape
+func cryptBlocks(c code, key, dst, src *byte, length int)
+
+var useAsm = hasAsm()
+
+func newCipher(key []byte) (cipher.Block, error) {
+	if !useAsm {
+		return newCipherGeneric(key)
+	}
+
+	var function code
+	switch len(key) {
+	case 128 / 8:
+		function = aes128
+	case 192 / 8:
+		function = aes192
+	case 256 / 8:
+		function = aes256
+	default:
+		return nil, KeySizeError(len(key))
+	}
+
+	var c aesCipherAsm
+	c.function = function
+	c.key = c.storage[:len(key)]
+	copy(c.key, key)
+	return &c, nil
+}
+
+func (c *aesCipherAsm) BlockSize() int { return BlockSize }
+
+func (c *aesCipherAsm) Encrypt(dst, src []byte) {
+	if len(src) < BlockSize {
+		panic("crypto/aes: input not full block")
+	}
+	if len(dst) < BlockSize {
+		panic("crypto/aes: output not full block")
+	}
+	cryptBlocks(c.function, &c.key[0], &dst[0], &src[0], BlockSize)
+}
+
+func (c *aesCipherAsm) Decrypt(dst, src []byte) {
+	if len(src) < BlockSize {
+		panic("crypto/aes: input not full block")
+	}
+	if len(dst) < BlockSize {
+		panic("crypto/aes: output not full block")
+	}
+	// The decrypt function code is equal to the function code + 128.
+	cryptBlocks(c.function+128, &c.key[0], &dst[0], &src[0], BlockSize)
+}