General practitioners' (GPs') anti-smoking advice promotes patients' smoking cessation but little is known about how GPs use their short consultations to give advice. We used semi-structured interviews with 27 UK GPs to investigate how GPs believe they should advise smokers to stop and the reasons underpinning these beliefs. GPs reported a limited repertoire of techniques for dealing with smokers who were not motivated to stop. They also reported using confrontational advice-giving styles with patients who continued to smoke despite suffering from smoking-related illnesses. GPs might find it easier and more rewarding to discuss smoking with patients if they possessed a greater range of skills for dealing with non-motivated smokers.