To examine memory for sexual expenences, the authors asked 37 sexually active, nonmonogamous, heterosexual college students to complete an e-mail diary every day for 1 month. The diary contained questions about their sexual behaviors. Six to 12 months later, they returned for a surprise memory test, which contained questions about their sexual experiences from the diary phase. They were asked about their sexual partners, the types of sexual experiences they had, and condom use. Participants underreported the number of partners they had, but they overreported both sexual experiences and condom use. The results have implications for both sexual health educators and for people who engage in high-risk sexual behaviors.