The present study relates to three aspects of quality of care in general practice: attention paid to somatic aspects, patient orientation and risk of unnecessary harm. Quality of care had been measured by (a) a written simulation of patient-doctor encounters, which includes five patients and (b) rating procedures. The study has been carried out in two steps. Firstly several aspects of peer consultation have been investigated in a group of 184 doctors (response rate: 83%), who had their vocational training in the department of General Practice of the University of Utrecht. One third of the GPs consulted colleagues frequently and continued to do so for long periods, dealing systematically with a variety of problems, one third did so infrequently or unsystematically, and one third did little or no consulting at all. A relationship was found between the type of practice and consulting behaviour: 20% of those who practice alone never consulted peers, whereas those in group practices and health centres are accustomed to do so regularly. Secondly, 49 doctors were selected from the 184 mentioned above. The 49 did not differ from the remainder in several relevant aspects such as practice setting, subscription to medical journals, etc. Peer consultation seems to have a direct relationship with the quality of attention paid to somatic aspects; GPs who do not consult among peers in any way display a lower quality of attention to somatic aspects in comparison to the others. In this study these GPs are all solo physicians.(ABSTRACT TRUNCATED AT 250 WORDS)