This study aimed to evaluate the effect of a motivational, minimal intervention approach to smoking cessation in an open, randomized design conducted by nurses as routine work in a lung clinic. Subjects who smoked less than 10 cigarettes x day(-1), and subjects who smoked > or = 10 cigarettes x day(-1) and who had refused to participate in a smoking cessation trial with nicotine replacement therapy, were randomly allocated to a motivational approach to smoking cessation or to a control group. The motivational approach consisted of a nurse-conducted 5 min consultation concerning reasons to quit smoking, brochures about smoking cessation and advice about how to quit. After 4-6 weeks, subjects in the motivational group received a letter encouraging them to quit smoking. After 1 year, all subjects were contacted by phone and smoking status reported. Subjects claiming to be abstinent attended the clinic for carbon monoxide verification. A total of 507 subjects were enrolled, 254 in the motivational group and 253 in the control group. The mean age of the motivational group was 51 yrs, 50% were males and they smoked a mean of 13 cigarettes x day(-1). The mean age of the control group was 53 yrs, 61% were males and they smoked a mean of 12 cigarettes x day(-1). At the 1 year follow-up, the success rate for point prevalence (no smoking at 1 year and during the preceding month) was 8, 7% in the motivational group versus 3.6% in the control group (p=0.025). The 12 months sustained success rate (no smoking at all during the year) was 3.1 versus 1.2% (p=0.22). The point prevalence for light smokers (<10 cigarettes x day(-1)) was 13.9% in the motivational group versus 6.3% in control group (p=0.12), and for heavy smokers (10 or more cigarettes x day(-1)) 5.2% versus 1.9% (p=0.20). In conclusion, the effect of this nurse-conducted, minimal intervention, motivational approach seems promising as the quit rate at 1 year follow-up had doubled.