The psychosocial and behavioral determinants of smoking cessation from late adolescence to early adulthood were investigated in a sample of 711 individuals followed from 1990 (grade 12) to 1995. Analyses stratified by sex indicated that female smokers were more likely to quit 5 years later if they had fewer friends who smoked, less parental approval of their smoking, weaker intentions to continue smoking, higher smoking resistance self-efficacy and better grades at grade 12. Several of these associations could be accounted for by smoking quantity. Similar analyses for male smokers indicated that those who eventually quit were more likely to have fewer cigarette offers, weaker intentions to smoke, better grades and an intact nuclear family at grade 12. The associations for males could not be explained by smoking quantity. Interaction analyses showed few significant sex differences in the predictors of smoking cessation. Results suggest that cessation programs should continue to target parental and peer influences, as well as skills at resisting social influences to smoke, through late adolescence, but do not indicate that such programs need to be adapted to the special needs of male and female smokers.