Working with data from the decadal US Census and the annual American Community Survey (ACS), the authors document four decades of increasing participation in registered nursing among US men and explore reasons for this change. Increasing educational attainment, rising labor demand in health care, rising urbanization, and liberalizing gender role attitudes explain approximately 50% of the growth. Results show that a large component of the increase occurs when men switched into nursing during their 20s and early 30s. Important countervailing factors include poor early labor market conditions and immigrant inflows, both of which are associated with less movement into nursing by men. The authors discuss the implications of their findings for policies that encourage men to take up high growth, non-traditional skilled jobs.