It was the aim of the study to develop a method that would fairly reliably predict abdominal involvement in patients with Hodgkin's disease. Using sonography (SG), computerized tomography (CT) and clinical findings we wanted to restrict laparotomy to patients with a high probability of abdominal involvement. 145 patients of the therapy study HD-82, who had preoperative abdominal SG or CT, were analyzed. All had a laparotomy, 61 had a splenectomy and 9 a partial splenectomy. The incidence of abdominal involvement was 36%. Using 2 X 2 contingency tables as well as the X2-test 7 out of 13 parameters tested had a highly significant correlation to abdominal involvement. These 7 parameters were analyzed with the linear-logistic regression model of COX. The three most valuable individual parameters "abdomen in SG and/or CT abnormal", "B-symptomatology" and "involvement of the hilar lymphnodes of the lung" contain almost all the information concerning abdominal involvement. All the other parameters are no longer significant when used in combination with these three and thus can be disregarded. For practical purposes one can omit the "B-symptomatology" as well, because the combination of the other two parameters has the smallest number of false positive results, while the number of false negative results is only slightly increased. Using these data we developed a decisional model for selective laparotomy, which allows a 50% reduction of laparotomies. This method can only be used in combination with a therapy concept that contains chemotherapy for all patients.