Chocolate does not contain any caffeine. This is an urban
legend. Caffeine is often confused with another alkaloid that has
similar effects. The alkaloid is Theobromine, which is the active
ingredient in chocolate and is toxic to dogs.
Chocolate does indeed contain caffeine. The amounts however are
fairly small. The amount of caffeine that chocolate contains will
depend on the bean it is made with. Cocoa beans contain between 0.1
percent and 0.7 percent of caffeine in them.