Objectives : This study was carried out to understand the prevalence and risk factors of green tobacco sickness (GTS) among Korean tobacco harvesters. Methods : The authors conducted a questionnaire among the tobacco harvesters (1,064 persons from 555 out of 723 tobacco harvesting households) in Cheongsong-gun for 4 days from May 7 to 10, 2002. Results : The study subjects were 550 males and 514 females. The recognition and experience of GTS up until 2001 were 96.4% and 61.9%, respectively. The prevalence of GTS in 2001 was 42.5%, and was significantly higher in females than in males (59.0% vs. 26.6%, p<0.01). The incidence density of GTS according to the number of workdays in 2001 was 12.3 spells/100 person..days. The GTS symptoms reported by the tobacco harvesters in 2001 were dizziness in 441 cases (97.6%), nausea in 414 (91.6%), headache in 349 (77.2%) and vomiting in 343 (75.9%). The use of gloves, hat and wristlets, sweating at work and the number of working hours significantly increased the prevalence of GTS (p<0.05). Multiple logistic re- gression analysis was used to determine the factors significantly associated with GTS. Odds ratios for smoking, working over 10 hours and sweating at work were 0.26 (95% CI:0.19-0.35), 1.64 (95% CI:1.26-2.14) and 1.60 (95% CI:1.14-2.25), respectively. Of those who reported GTS in 2001, 311 cases (68.8%) underwent treatment from their local medical facilities. Conclusions : In Korea, there are many tobacco-harvesting households, and most may be stricken with GTS. More extensive epidemiological studies, including the incidence and associated risk factors, are expected and a surveillance system including measurements of cotinine in urine should be conducted.