Tobacco smokers suffer from postoperative complications after surgery more often than non-smokers. This has been proven in both general, orthopaedic and plastic surgery. In recent years, preoperative smoking cessation has been evaluated in several studies. It has been shown that smoking cessation four to eight weeks prior to surgery significantly reduces wound healing complications. There are still some unanswered questions concerning the necessary length of preoperative smoking cessation to affect the complication rate. There is also lacking evidence on smoking cessation in emergency surgery, and the cost-effectiveness of a smoking cessation intervention programme. Therefore, further studies on preoperative smoking cessation are needed. Three randomised multi-center trials in greater Stockholm are planned to further elucidate these questions.