The factors that influence the interpretation and treatment of psychosocial complaints by general practitioners are discussed. The assessment of complaints differs considerably from one GP to another, in the sense that one will attach significance to psychological and sociological factors in many more cases than another. We investigate the effect of physician characteristics and their styles of communication on their bias over psychosocial assessments and treatment, and the way these effects are interrelated. The interpretation and eventually the treatment of complaints by 30 GPs (complaints presented at approx. 50 consultations per GP) were studied. Data of treatment and communication were collected from observation of the videotaped consultations, data of interpretation were collected on questionnaires for each consultation; doctor characteristics were inventarized by questionnaire. The following results can be reported. When a doctor communicates with a patient in an open manner, more complaints are interpreted as 'non-somatic' and treated as such. The same is the case among doctor's with a 'general medical' approach, rather than a 'clinical' one, when we look at interpretation. The effect on treatment is less marked. Practice characteristics and a GP's subjective feeling of competence have greater consequences for treatment than for judgement. There is not much interaction between the discerned effects.