Does the gardasil shot prevent genital warts?

Yes, but not all. Gadasil has antigens from 4 different HPV types. 2 of those are the common causes of genital warts. The other 2 are for cervical cancers. Unfortunately, if I remember correctly, there are over a 100 types of HPV. Many are harmless, but some do cause Cervical cancer and genital warts. So, you still need to practice safe sex to protect yourself.