Accuracy of recall of the number of sexual partners individuals had over a period of one month, three months, six months and one year was studied in a group of 285 young, single, heterosexual adults. Self-reports of the number of partners were obtained on a weekly basis and then compared with recall of behavior over longer time periods that overlapped the weekly measures. For individuals who claimed abstinence or who claimed to be monogamous, accuracy of recall was relatively high, especially at the shorter time frames. Level of education was related to accuracy for claimed abstainers, such that lower levels of education were associated with lower accuracy of recall. Accuracy rates for individuals who reported having multiple sexual partners tended to be lower and were found to be related to one's propensity to engage in casual sex.