How can I repair a cabinet door that won't stay shut?

Hi Betty I have several old cabinets in my kitchen with the same problem so I purchased little magnet clasps, they work great and are easy to install.

Hinges could be bent....DSS changed our hinges and they shut perfectly. Be sure the door is not hitting something you have stored below your sink.

My parents have these. They work well and have stood the test of time.

https://www.google.com/aclk?sa=l&ai=DChcSEwjl79ejurjnAhVA_uMHHQvbAlUYABAMGgJ5bQ&sig=AOD64_0_xx51pooaekCdIP4a0gZfdA_UTA&ctype=5&q=&ved=0ahUKEwijptKjurjnAhUDca0KHWtlAOYQpysICw&adurl=

Remove and clean the old hinge. Sometime debris and paint won't allow it to close all of the way. If that is not the issue. Take old hinge to Home Depot or hardware store and get one that matches up to size and holes if not. If you can't find one with same size holes, fill the old holes with wood glue and small pieces of wood shaved off of scrap wood. Trim to size when dried next day and drill new holes.

Hi! Is the door sagging on the hinge? Is it lining up with the frame. Sometimes the hinge needs to be tightened up.

IGrandmasHouseDIY has a good idea also. I put some of those on a cupboard I have in my TV room.

Magnet catches are the cheapest and simplest solution. Replacing the hinges would be next.

try magnets

HERE are the magnets on Amazon. You could also try a child lock, BUT... probably not the most attractive :)