Craving and nicotine withdrawal syndrome (NWS) are components of the tobacco use disorder in DSM-5. They both appear after smoking cessation or an abrupt reduction in tobacco use, and they are associated with both short and long-term smoking-cessation outcomes. The aim of the present study was to examine the association of craving and withdrawal with smoking cessation at the end of the treatment and relapse at 3 months follow-up in a Spanish sample of smokers. The sample comprised 342 smokers (37.7% men; 62.3% women) receiving a cognitive-behavioral treatment for smoking cessation. The assessments of craving and withdrawal were conducted using the Minnesota Nicotine Withdrawal Scale. Abstainers at the end of the treatment, compared to non abstainers, showed significantly lower post-treatment withdrawal, and post-treatment craving. Furthermore, they had lower scores in pre-treatment nicotine dependence. Among abstainers, craving decreased significantly from pre-cessation levels, while in those participants who did not quit smoking it remained on the same levels. High nicotine dependence was a predictor of smoking at the end of the treatment, whereas high nicotine withdrawal predicted relapse at 3 months. Findings support the robust role of craving and NWS in smoking cessation and relapse, although they differ in their specific patterns of change over time.