In this study the authors describe the investigation of a 1992 outbreak of green tobacco sickness, a form of nicotine poisoning from dermal exposure, among 47 tobacco workers in a five-county region of central and south-central Kentucky. Cases were identified through medical record searches at participating hospitals, as well as from reports submitted to the Occupational Health Nurses in Agricultural Communities program. A case-control study was undertaken to assess risk factors for green tobacco sickness. In a 20-min telephone interview, 40 cases and 83 controls responded to questions contained in a questionnaire. In 1992, 47 persons (3 were under age 16 y) in the study region sought medical treatment for green tobacco sickness. Twelve persons were hospitalized and 2 required intensive-care treatment. The crude incidence in 1992 was 10.0/1,000 tobacco workers. In 1993, 66 cases (7 were under age 16 y) of green tobacco sickness were identified in the study region (i.e., annual incidence of 14.0/1,000). A case-control study demonstrated that ill workers were younger, and were more likely to have worked in wet conditions, compared with workers who were not ill. Green tobacco sickness is a common problem among tobacco workers that may be prevented by avoiding work in wet tobacco or by use of protective clothing. Children younger than 16 y of age represented 9% of the green tobacco sickness cases in 1992 and 1993. Current occupational safety and health laws do not address protection of tobacco workers with respect to green tobacco sickness.