No, there is no evidence that cracking your knuckles leads to arthritis.

Here is some more input from FAQ Farmers:

鈥racking your knuckles wears away the cartilage between the joints over a long period of time. This is one of the causes of arthritis. Other causes of arthritis are completely unrelated, like for example, you can inherit it from your parents, or get it because of a disease like Lupus. So, I guess if you might get it anyway, and you might not know if it was your's or your parents fault, go ahead and crack away.

鈥on't listen to those people that tell you cracking your knuckles will cause you to have arthritis. At this point it's just a speculation, not wild, but certainly not founded on anything but misconceptions. All you're doing is playing with the physiology and chemistry of your body a bit. There are good and bad sides to this. Here's a rather complete site if you want to read more (which keeps me from typing it all out): howstuffworks.

鈥o, of course it doesnt. A study focused on 300 habitual knuckle crackers found no evidence linking knuckle cracking and arthritis. Chronic crackers did suffer other harm, including soft tissue damage and loss of grip strength. This damage is usually minor, however, and cracking your knuckles actually has some benefits -- you'll feel looser and enjoy more mobility in your joints immediately after popping.

鈥o, it only elongates the joints over time and gives you the appearance of longer fingers.