The prevalence of Green Tobacco Sickness (GTS) among shade tobacco farmworkers in Connecticut is unknown. We conducted a study to determine the prevalence of GTS in farmworkers working in shade tobacco fields who presented for clinical care at medical student-run clinics. A retrospective chart review of the tobacco workers seen at Farmworkers’ Clinics during 2001 was instituted in this study. Although GTS was not clinically diagnosed in any of the patients, we found 15% diagnoses that could be attributed to possible GTS by ICD-9 code review. Using a stricter GTS case definition, the frequency rate decreased to 4%. Nonsmokers were significantly more likely than smokers to report GTS-like symptoms (P < 0.01). Isolated symptoms of headache and dizziness were significantly more frequent among nonsmokers than smokers (P < 0.05). In conclusion, cases of possible GTS were found in Connecticut shade tobacco workers. Nonsmokers were more at risk to have possible GTS than smokers.