Dermal absorption of nicotine by people harvesting tobacco may cause an acute intoxication called green tobacco sickness. Although Brazil is the second largest producer of tobacco in the world, green tobacco sickness had not been reported in the country to date. We conducted a 1:1 matched case-control study among persons involved in tobacco farming to determine the occurrence of green tobacco sickness in the northeast region of Brazil and to identify the risk factors involved. A case-patient was a person who received a diagnosis by health professional of acute intoxication during the study period and had a cotinine level over 10 ng/mL detected by High Performance Liquid Chromatography. We identified 107 case-patients. The main signs and symptoms observed were dizziness, weakness, vomit, nausea and headache. Independent risk factors identified were being male, a non smoker and having worked in the harvest of tobacco leaves. Case-patients had higher median urinary cotinine levels than controls (p < 0.05). Epidemiological and laboratory data indicate for the first time the occurrence of green tobacco sickness in Brazil.