Most studies on changes in female behavior and preferences across the menstrual cycle have been conducted in samples comprised of largely white undergraduate students from Western populations. The present study examined cyclical shifts in reactive, preventive and anxious jealousy in a sample of 71 Afro-Caribbean women from Curaçao, a country in the Caribbean. We expected that, because of the risk of conceiving, especially preventive jealousy would be relatively high when fertile to safeguard the male’s protection, provisioning and investment. The results showed that, when fertile, women experienced indeed particularly more preventive jealousy, and also somewhat more anxious jealousy, but not more reactive jealousy, than when non-fertile. In addition, preventive jealousy was higher the later the age of the first menarche. We discuss possible explanations for the functionality of preventive jealousy during the fertile phase of the cycle, and for the functionality of such jealousy among women with a slow life history strategy.