Indonesia has been experiencing impressive economic growth and rapid urbanization in recent years. However, urbanization could affect income inequality through people’s movement from rural to urban areas. Using the 2010 National Labor Force Survey (Sakernas) in Indonesia, this study examines how monthly wages are distributed between male and female workers and tests whether a wage gap exists between them. Regression results reveal that urbanization tends to benefit male workers more favorably, in terms of monthly wages, than female workers. The wage gap tends to be wider among younger workers, particularly among those who are underemployed and severely underemployed. It is also greater among public sector workers than those in the private sector. Gender wage gap in Indonesia is mainly due to gender discrimination. An act to equalize opportunity and wages among workers, especially in the public sector, is proposed.