Helping patients modify risky health behaviors, including cigarette smoking, at-risk alcohol use, sedentary lifestyle and unhealthy diet, is a common and sometimes frustrating task. Motivational interviewing was developed from the notion that simple advice usually does not lead to behavioral change and may be even misperceived by patients. Based on active listening and an empathic attitude, some principles of motivational interviewing may be easily adapted to a primary care consultation. These principles facilitate positive, relaxed and constructive atmosphere for behavior change discussions and have been associated with promising results. This article presents key concepts of motivational interviewing such as ambivalence, resistance and stages of change, illustrated with practical examples.