Early detection of cancer can lower mortality rates. Detection tests are available for some cancers such as breast and cervical cancer. Unrealistic optimism can affect compliance with health recommendations. Factors such as past experience (personal or at workplace) and perceived control over the disease influence unrealistic optimism. The purpose of this study was to examine the influence of past experience and perceived control over disease on unrealistic optimism towards breast and cervical cancer, and to examine the effect of unrealistic optimism, perceived control over the disease, and past experience on intentions to undergo screening tests. The study design was quasi-experimental correlative. Past experience was measured among 3 groups of women living in Tel-Aviv ranging in age from 21 to 60 years: oncology nurses (n= 50), obstetric nurses (n= 50), and laywomen (n= 50). These groups were presumed to differ from each other in the extent to which they were aware of cancer. In addition, the 2 types of malignancy represented different levels of awareness. Questionnaires were used to measure the study variables. Experience had a strong impact on unrealistic optimism with both cancers. However, the cancers differed in the impact of unrealistic optimism on behavioral intentions. With breast cancer (the more frequent), there was only a main effect of unrealistic optimism. A 3-way interaction was found with cervical cancer. The results indicate that unrealistic optimism plays a role in predicting participation in early detection testing and should be considered as an influencing factor in health-promoting plans.