To characterize dermatitis related to pesticide exposures among banana plantation workers in Panama, the authors studied 281 workers seen at The Occupational Health Department of the Social Security Hospital of Changuinola and Puerto Armuelles between 1988-1992 and in 1993. Exposure data were collected through a standardized occupational health history. Physical examination, a standard patch test, and a pesticide patch test (PPT) were carried out. Of the 244 men (86.8%) and 37 women (13.2%), 17 and 37, respectively, were packing station workers. The other 227 men were field workers, exposed to many pesticides (propiconazole, maneb, chlorothalonil, dithane, dalaphon, ametrine; and gramoxone). The 54 packing station workers were exposed to imazalil, thiabendazole, aluminum hydroxide solutions, and formaldehyde. The hands were the most frequently affected areas (82%), followed by the thorax and abdomen (9%), legs and feet (5%), and genital area (4%). There were 78 positive PPTs (27.8%) in 281 patients. The most frequent reactions were to the fungicides chloro-thalonil (51.4%), thiabendazole (12.8%), imazalil (10.2%), and aluminum hydroxide (10.2%), which accounted for 85% of all positive tests. The majority of the cases were related to exposures to fungicides; 246 with negative PPTs were classified as irritant contact dermatitis patients; 48 controls were negatives. Contact dermatitis related to pesticide exposure is a significant occupational health problem for banana workers in Panama.