Why is my MacBook shift key always pressed?

Turn the computer off, take off the shift key, and reboot the Macbook. If the computer boots as it should, make sure to reinstall the key correctly. I guess the scissor mechanism or the metal arm under the key is not well fixed.

"I had a similar problem, the left shift key appears to be damaged, it doesn't feel 'right' when pressed. The machine works perfectly with a USB keyboard. Apple are only interested in replacing the whole keyboard, and say they may need to replace the top cover too. Not cheap! I'm not too confident about fixing the key myself, so I used a software fix.

I downloaded and installed KeyRemap4MacBook, then disabled the left shift key, clicked on the 'Reload XML' button, and all now works OK, except i can only use the right shift key, which isn't a huge issue. Caps lock is still OK.

This fix is at the software level, so you still need to hold down the option key to bypass safe boot. You also need to go into the system preferences and add KeyRemap4MacBook as an application that should start on login."

"I spilled some milk all over my keyboard a month ago. It has slowly been improving (keyboard didn't used to work, but now it works near perfectly). The only problem that I still have is that the left shift button seems to be stuck.

It was mentioned above in this discussion that the c or esc button needs to be held down to not boot up in safe mode with a stuck shift key. This did not work for me. I held down the option key and that worked for me. Finally out of Safe Mode! I'm on version 10.7.5"

during booting < after restart> press the c key and it will log in as normal>>> also you could use a external key board>