1905 smokers were investigated from a random sample of 4424 persons among the Swedish population interviewed in 1974 and 1981. On average, 28% of those smoked in 1974 had stopped smoking by 1981. A multivariate method was used to study whether socioeconomic and demographic factors, tobacco consumption level or health contributed to changes in smoking behaviour. Most successful in smoking cessation were senior salaried employees (35% quit), well educated persons (33% quit) and those who smoked less than ten cigarettes per day (36% quit). On the other hand, only 20% of divorced parents with children succeeded in smoking cessation. Tobacco consumption turned out to be the most important variable for explaining the variance. The probability of smoking cessation increased by 40% if one smoked less than 10 cigarettes per day. The low explained variance, 6%, of this multivariate approach indicates, however, that socioeconomic factors have only marginal effects on the decision to stop smoking. It seems more likely that many factors, e.g. demographic, socioeconomic, motivational, self-efficacy, social and therapeutic support, nicotine dependence etc. act together in a complex way.