The purpose of this survey is to study the prevalence and motivating factors of smoking among 1,372 students at a rural middle school in Taiwan. The prevalence of smokers for total, male, and female students is 5.7, 11.5, and 0.4%, respectively. Prevalence increased with age and grade among males, but no significant differences were found among females. Prevalence was higher among students from nuclear families than those from extended families (OR = 2.8, 95% C.I. 1.4-5.5). Prevalence was also higher among students from families with very strict parental control or very little parental control (OR = 4.25, 95% C.I. 2.24-8.08). The majority (70-80%) began smoking during primary school. Smokers who had attempted abstinence in the past had a better understanding of the hazards of smoking and smoked less frequently and with lower average consumption (P < .05). For 60% of the students the first source of cigarettes was friends or classmates; only 22% bought them. Health education increased understanding of the hazards of smoking (OR = 2.2, 95% C.I. 1.10-4.45). In conclusion, the primary factors that affect adolescent smoking are age, family structure, abstinence experience, strictness of upbringing, family influence, peer pressure, and health education.