Marital breakup has been associated with numerous behavioral problems in children, such as sexual risk behaviors. This research is the first to examine sexual behaviors of Spanish adolescents related to whether their parents were married or divorced. Participants were 342 boys and girls aged between 14 and 18 years. The sample provided confidential information about their sexual behavior and birth control methods. Significant differences were only found in percentages of adolescents who had engaged in mutual masturbation, intercourse, or oral sex, and who had practiced these sexual relations in the last six months, in both cases, they were higher when the parents had broken their marital relationship. Regarding adolescents of divorced parents, engaging in intercourse is more likely in older teenagers who live with a stepparent. Moreover, older adolescents who were younger when parents divorced and who live in a reconstituted family, have more sexual partners. These and other findings are discussed.