The chances of getting an STD from a one-night stand depend on whether it was protected or unprotected sex. The chances of getting an STD from one unprotected encounter with a partner who is infected with syphilis, gonorrhea, or chlamydia are about 30 percent.

Can you get an STD from one time?

STDs arent transmitted every time you have sex, but they can be transmitted any time you have sex. You can get an STD the first time you have sex. But there are no STDs that will always be transmitted every time someone has sex.