Research on romantic jealousy and self-esteem mostly relies on the measurement of explicit (i.e., conscious, deliberate) aspects, without taking recent developments of the measurement of implicit (i.e., automatic) aspects into account. In this study (N=154), we applied several measures of romantic jealousy and self-esteem (explicit, implicit), finding sex-specific as well as measurement-specific effects. Men (but not women) higher in jealousy had lower explicit self-esteem, whereas women (but not men) higher in jealousy had higher implicit self-esteem, but only when using the Implicit Association Test (whereas not the Initial Preference Task) for measuring implicit self-esteem. Individuals with damaged (i.e., low explicit and high implicit) self-esteem were more jealous than those with fragile (i.e., high explicit and low implicit) self-esteem. This differential effect was due to higher implicit self-esteem among women, whereas lower explicit self-esteem among men. These novel findings not only add to the expanding literature on romantic jealousy research, but also to research on self-esteem discrepancies.