We followed 235 adults for one year after a self-initiated attempt to stop smoking cigarettes. Relapse rates were much larger than expected in the early days and weeks after the quit attempt. Approximately 62% had relapsed by 2 weeks after their quit dates. Those who smoked any cigarettes at all in the post-cessation period (i.e., lapsed) had a 95% probability of resuming their regular pattern of smoking subsequently. Shorter periods of abstinence on prior quit attempts, greater pre-cessation consumption of alcoholic beverages, and lower pre-cessation levels of confidence in quitting were related to relapse. In addition, abstainers who reported decreased confidence after cessation concerning their ability to maintain abstinence were more likely to relapse thereafter. The presence of a greater proportion of smokers in the subjects' environment also increased the likelihood of relapse. Demographic variables such as age, gender, and education level did not predict relapse. Likewise, neither baseline psychosocial stress levels, nor post-cessation increases in stress were related prospectively to relapse. Clinical implications of finding are discussed.