Absolutely! A leaking roof, left un-repaired or not replaced, will cause damage to the structure that makes up your home. A roof is a home's first line of defense against the elements, this is why it's so important to repair or replace the roof BEFORE any other work can take place.
Another problem with a leaking roof, is the possibility of mold. Mold is a very dangerous health hazard and it thrives in any wet environment.
Don't forget to call CRC at 410-ROOF THIS at the first sign of a roof leak.