The author finds evidence of a downward-sloping labor supply curve for urban areas in Peru from cross-sectional household data for 2002 and pooled data for available years from 1985 to 2000. Individuals respond to lower hourly earnings with an increase in the quantity supplied of work hours. This behavior would help to explain the increasing trend in average work hours in Peru (this average for male workers in Lima, the capital city, rose from 50.5 to 53.9 weekly hours between 1985 and 2000; meanwhile, 33.4% of workers had weekly schedules above 60 hours in 2002). Another finding is the increase in hours supplied due to pressure from the more numerous cohorts recently entering the Peruvian labor market. © 2008 The Author Journal compilation © 2008 Blackwell Publishing Ltd.