We estimated the prevalence and incidence density (ID) and the risk factors of green tobacco sickness among minority farmworkers in North Carolina. Using a prospective surveillance design, 182 farmworkers were interviewed up to 5 times at biweekly intervals in 1999. The green tobacco sickness prevalence was 24.2%, whereas the ID was 1.88 days per 100 days worked. Greater work experience (5+ years, ID = 0.87; first year ID = 2.41) and tobacco use (ID of 1.18 vs 2.39) were negatively associated with green tobacco sickness. Task (eg, priming ID, 4.04; topping ID, 1.86; barning ID, 0.62) and working in wet clothing (25% of workdays ID, 2.97; fewer than 25% of workdays ID, 1.29) had the largest effect. More effort must be directed toward preventing this occupational illness that affects workers who have little control over workplace safety.