Representative samples of the Czech population were surveyed with regard to sexual behavior in 1993, 1998, 2003, and 2008 (N = 7,720). Lifetime prevalence of Heterosexual Anal Intercourse increased from 1993 to 2008 (16.6% to 19.7% among women, 15.7% to 25.3% among men). Anal intercourse was associated with lifetime number of sex partners, current masturbation, and histories (prevalence of which increased from 1993 to 2008) of homosexual sex, prostitution, venereal disease (adjusted for number of sex partners), and women's sexual dysfunction. The authors discuss the possible reasons for the increasing prevalence and the associations. Multivariate predictors of ever having a sexual dysfunction or a venereal disease are also presented.