Exploratory laparotomy with splenectomy was performed before or after multiple chemotherapy in 182 patients with clinically localised Hodgkin's disease in clinical stages IB, II3A, IIB, III A and III B. There was a 50% probability of clinically not diagnosed infradiaphragmatic involvement in patients with clinically localised stage IB, II B or II3A. Restaging was necessary in 20% of patients with clinical stage III, because infradiphragmatic involvement was histologically not demonstrable. Infradiaphragmatic involvement occurred in 12% of patients who had received six chemotherapy cycles according to the MOPP scheme, before exploratory splenectomy. When chemotherapy produced complete clinical remission, only 2.7% patients had any infradiaphragmatic involvements. Exploratory laparotomy with splenectomy is not required, therefore, in such patients.