Background: Medical peri-operative consultation plays an important role in the practice of the internist. It represents 13-33% of the total consultation done by the internist. The value of preoperative consultation by the internist is still unclear and the place of the consultations is under discussion.Methods: Consecutive medical consultations - by internist-intensivists from the surgical ICU - of 408 patients in the department of Surgery of the University Hospital Groningen were retrospectively analyzed, with specific attention to the consultation request, the consultation report and the outcome of the consultation.Results: The main problems were cardiac (34%) or pulmonary (20%). In 78% well defined questions about the patients were asked and in 29% of the preoperative requests, the requesting surgeon asked specific advice about diagnosis and management. In 49% the requesting physician asked for an 'evaluation' of the patients. Of all consultations 271 (67%) were preoperative consultations. In 12% the findings of the preoperative consultation had a significant impact on the course of the patient, whereas in 7% of the preoperative requests the operation was postponed. The consulting internist recommended in 2% to cancel the operation for this admission, which was shared by the surgeon and anesthesiologist. In 10% of all cases new diseases or processes were diagnosed, or were found not to be treated adequately before consultation, so the diagnosis or management was changed.Conclusions: Our data show that (semi-) elective consultations by internists at the department of Surgery, on indication of the surgeon, changes the course of a significant percentage of patients. (See Editorials p. 1 and p. 4) Copyright (C) 2000 Elsevier Science B.V.