In the last four decades, women have made major inroads into occupations previously dominated by men. This paper examines whether occupational feminization is accompanied by a decline in wages: Do workers suffer a wage penalty if they remain in, or move into, feminizing occupations? We analzye this question over the 1990s and 2000s in Britain, Germany and Switzerland, using longitudinal panel data to estimate individual fixed effects for men and women. Moving from an entirely male to an entirely female occupation entails a loss in individual earnings of ten percent in Britain and four percent in Germany, but is not significant in Switzerland. The impact of occupational feminization on wages is not linear, but sets apart occupations holding less than 40 percent from those with more than 60 percent of women. Only moving into the latter incurs a wage penalty. Contrary to the prevailing idea in economics, differences in productivity – human capital, job-specific skill requirements and time investment – do not fully explain the wage gap between male and female occupations. This finding suggests that wage disparities across male and female occupations are in part due to unequal gender norms.