A contingent valuation approach to assess the health effects of pesticides among Nicaraguan vegetable farmers is presented. Farmers' valuation of health is measured as willingness to pay (WTP) for low toxicity pesticides. Results show, that farmers are willing to spend about 28% of current pesticide expenditure for avoiding health risks. The validity of results is established in scope tests and a two-step regression model. WTP depends on farmers' experience with poisoning, income variables and pesticide exposure. The results can help in targeting of rural health policies and the design of programmes aiming to reduce negative effects of pesticides.