Background: Smoking is a preventable cause of increased morbidity and mortality. Therefore, interventions have been used to assist smokers in overcoming their addiction. The aim of the study was to describe factors associated with smoking cessation, in patients applied to our smoking cessation (SC) unit in 1999, in a prospective study. Methods: Patients were followed-up during two years. Detailed medical history, Fagerstrom test, Hospital Anxiety and Depression (HAD) scale questionnaire, Motivation scale and replacement therapy were systematically recorded. Results: Three hundred patients (58% men, 42% women) applied to the SC unit from January to December 1999. The mean age was 42yrs old. They smoked in average 24 cig/d. Mean duration of smoking was 20 years. Fagerstrom score was 5.86 (min 0; max: 10). Patients seemed to be more anxious (score 9.6) than depressed (5.09), according to the HAD score. 79% of them received both psychosocial intervention, pharmacotherapy and nicotine replacement therapy. 66% of patients were followed-up (n = 198). Two years later, the smoking cessation rate was 12% (n = 36). Motivation, Fagerstrom and HAD scores were not associated with the quitting rate. Quitting rate was higher (25.9%) in patients who attempted to quit smoking for the first time than in others (19%). By contrast, the quitting rate was significantly associated with age (P = 0.03). Conclusion: Success to quit smoking was positively associated with age, and negatively with alcohol dependence. (c) 2004 Elsevier Ltd. All rights reserved.