 COPD is an increasing cause of death and morbidity and smoking is its primary cause. Professional smoking cessation treatment is very cost-effective and therefore recommended by national guidelines. A controlled study demonstrated that a smoking cessation protocol in routine primary care, specifically targeted at patients with COPD SMOCC, doubled the quit rates. The incremental cost-effectiveness ratio ICER was Euro 1012 showing that the protocol was cost-effective. The protocol was tested under optimal trial conditions, but it is unclear if a large-scale implementation strategy is cost-effective. Therefore the present study investigates an implementation strategy in a 2-armed community intervention trial. General practices N150, 2700 smoking patients with COPD will be randomly allocated to the intervention or control condition. In the control condition the usual dissemination strategy of distributing guidelines and subsequent products through the professional channels journals, postgraduate education will take place. In the intervention condition a multifaceted implementation strategy wil be executed aimed at support of the general practice team outreach education by a facilitator, support for detecting smoking patients with COPD, provision of patient education materials, help deskwebsite, telephone and e-mail reminders. The research question is how cost-effective this implementation strategy is compared to usual implementation procedures. Primary outcome measures will be biochemically validated smoking abstinence at 12 and 18 months. Secondary outcome measures will be counseling contacts and counseling behaviour of professionals and cessation attempts of patients. A process analysis and evaluations by patients and professionals are an integral part of the study. A cost-effectiveness analysis taking a health care sector perspective will be performed and will show the expected costs per practice and an incremental cost-effectiveness ratio ICER. The study will last 34 months, the intervention period will take 18 months per practice. 