Recent research on African countries suggests their fertility transitions are slowing or reversing. Authors have suggested that this trend change may relate to widespread HIV/AIDS, but speculation abounds as to how the disease interacts with fertility. Different behavioral and medical mechanisms can lead to positive or negative correlations between HIV and fertility, and these correlations can be opposite on the individual and aggregate levels. This article provides a synopsis of the mechanisms relating HIV to fertility, attempting to describe their relative importance in affecting larger fertility trends. We discuss what outcome measures would be impacted by the different mechanisms, and suggest methods on how to study whether HIV plays a significant role in fertility trends. Case studies of several variables from three countries (Uganda, Burkina Faso, and Zimbabwe) show that fertility declines appear to stall during the height of the epidemics in these countries, and effects are larger depending on extremity of the epidemic. Indicators of other measures of fertility behavior suggest that women are attempting to avoid HIV while maintaining high fertility. While these results show suggestive evidence of fertility behavior changes in relation to the HIV epidemic, more rigorous empirical analyses are necessary to control for conditional effects.