As suicide rates have increased in rural areas in Brazil, it was postulated that pesticide exposure may play a role in this phenomenon. Our study compared the suicide mortality rates observed among agricultural workers from a pesticide-intensive area in Brazil to the suicide mortality frequency noted in three reference populations. In addition, hospitalization rates attributed to suicide attempts and mood disorders including depression in residents of the same agricultural area were compared to two reference populations. Finally, data on pesticide sales per agricultural worker were obtained for each city of Rio de Janeiro State and suicide mortality risk was then calculated according to the quartiles of pesticide sales per agricultural workers, using the first quartile as reference. Agricultural workers were at greater risk for lethality due to suicide when compared to all three reference populations. In addition, residents of the same study area showed higher hospitalization rates by suicide attempts and mood disorders than observed in comparison populations. Results also showed that the risk of death by suicide was significantly higher among agricultural workers who lived in areas of Rio de Janeiro State displaying higher rates of pesticide expenditure per agricultural worker. These results suggest that pesticide exposure may indeed increase the risk of suicide frequency, especially among agricultural workers.