Consultation length illustrates how general practitioners balance contradictory concerns such as productivity and quality, listening to patients, and handling their own stress. Important factors for consultation length are list size, characteristics of doctors and patients, and character of the problem. The purpose of this study of 463 consultations was to describe factors that are associated with short and long consultations and to examine the relative influence on the consultation length of patients' age and sex, character of the problem, continuity, and the 'doctor's speed'. A questionnaire was used for both doctors and patients. Short consultations were often made by younger male patients about physical problems, while long consultations often were made by older patients about problems with both psychological and physical dimensions. The 'doctor's speed' explained 22.5%, character of the problem 11.6%, and patient's age 2.9% of the variation in consultation length.