The past two decades have witnessed an explosion of interest in nonindependent mate choice, i.e. female choice that is influenced by the choices of other females. This research has focused overwhelmingly on mate choice copying, which occurs when a female is more likely to mate with a previously mated male and reject a previously rejected male. I review the theoretical constructs of nonindependent mate choice and mate choice copying, and evaluate the general hypotheses that have been proposed to account for the adaptive significance of mate choice copying, namely that it serves to bypass the costs of mate choice or improve the discrimination accuracy of females. I discuss the standard experimental protocols that are employed in the study of mate choice copying and review empirical studies that have been conducted to date. Strengths and weaknesses of the mate choice copying research program are highlighted, as well as possible directions for future research.