BACKGROUND The identified risks of smoking with regard to operated tissues are so elevated that it is clearly dangerous to operate a smoker when the proposed intervention is neither vital nor urgent. MATERIALS AND METHODS The aim of this prospective study was to evaluate a simple method of screening patients who smoke, with the evaluation carried out before agreeing to carry out free tissue transfer. The purpose of the testing was to hold the patient responsible for his actions and minimize smoking-related complications by cancelling or postponing the planned operation if the patient continued to smoke. Screening included use of a standardized questionnaire at the first consultation and detection of cotinine using a urine test strip 7 days before the scheduled surgery. Patients were informed that in the event of positive results, the operation would not take place. A six-week preoperative smoking cessation period was mandatory. RESULTS Seventy-six patients were included in this study. Among them, 25 (32.9%) reported being former smokers and 11 (14.5%) admitted in the initial questionnaire to being active smokers. Six patients (7.9%), including one self-reported non-smoker, tested positive for cotinine, and their operations were cancelled. CONCLUSION Screening using a questionnaire and cotinine detection appeared to constitute a simple, inexpensive, rapid and reliable test. It allowed us to refuse to operate 6 non-compliant patients and was thereby likely to diminish morbidity in the free tissue transfers carried out in our ward.