Research has shown male registered nurses (RNs) outearn their female colleagues by approximately $5,000 annually. The aim of this study was to explore differences in characteristics of female and male fulltime employed RNs, and to examine whether these differences help account for the female-male earnings gap in nursing. Specifically, the researchers tested whether the gender earnings gap could be explained by differences in career aspiration, workplace experience, time taken out of the labor force for child-rearing, and physical strength. While some evidence suggested motivational differences in career aspirations between female and male RNs exist, evidence supporting other hypotheses was not found. Given the expansion of nurses' roles in health care delivery, serious deliberations of how to respond to the earnings gap in nursing is warranted.