Objectives: To determine the impact of child sexual abuse (CSA) on adult sexual behaviors and outcomes over three age periods. Methods: A longitudinal study of a birth cohort born in Dunedin, New Zealand in 1972/1973 was used. Information on CSA was sought at age 26, and on sexual behaviors and outcomes at ages 21, 26, and 32. Comparisons were over the whole period from age 18 to 32, then for the three age periods from age 18 to 21, 21 to 26, and 26 to 32, adjusting for measures of family environment. Results: Overall, 465 women and 471 men (91.9% of the surviving cohort) answered questions about CSA. Contact CSA was reported by 30.3% of women and 9.1% of men. For abused women, significantly increased rates were observed for number of sexual partners, unhappy pregnancies, abortion, and sexually transmitted infections from age 18 to 21; with rates approaching those of nonabused over time. Conversely, for abused men rates were not significantly elevated in the youngest age period, but were for number of partners from age 26 to 32 and acquisition of herpes simplex virus type 2 from age 21 to 32. Conclusions: Gender and age are critical when considering the effect of CSA. While the profound early impact of CSA demonstrated for women appears to lessen with age, abused men appear to carry increased risks into adulthood. Practice implications: CSA is common and should be considered when young women present with unwanted conceptions or seek multiple terminations, and when men continue to have high risk sexual behavior into adulthood. Furthermore, if CSA is disclosed, sexual risks in adulthood need to be considered. (Contains 1 figure and 5 tables.)