The aim of this work was to carry out a cost evaluation of the home care programme for terminally ill cancer patients run by the Istituto Oncologico Romagnolo (I.O.R.) in the areas of Forlì, Cesena, Ravenna and Rimini (Romagna, Italy). To determine effective home care direct costs, we first selected 1 week of care as an observation unit. We then proceeded to assess the medical and nursing care units together with the clinical protocols administered for each patient. The Karnofsky Performance Status (KPS) was also assessed weekly. In this way, we calculated care costs for each patient and for each week as the sum of medical costs, nursing costs, treatment costs and other costs. A consecutive series of 574 patients were involved in the study from 1 April 1994 to 31 March 1995. A total of 5164 patient-weeks of care was provided, with an average cost per week of 177.6 Ecu. This weekly cost increased in the last 100 days of life (week -15 = 179.5 Ecu; week -8 = 188.3 Ecu; week -2 = 221.0 Ecu; P < 0.001). When single components were analysed in relation to total cost (treatment protocols, physician and nursing care) the increased global cost was found to be mainly attributable to the intensification in nursing care (21.8% of costs in week -15 vs 27.3% of costs in week -2). Examination of the relation between the cost of 1 week of care and KPS values clearly shows that healthcare costs increased as KPS decreased (from 152.2 Ecu with KPS > or = 60 to 292.6 Ecu with KPS < or = 20; P < 0.001). Home care costs were also seen to vary with some clinical characteristics and symptoms present when patients entered the study: asthenia, anorexia, nausea/vomiting, bedsores. Given the good results of home care for cancer patients in terms of quality of life, this method of cost accounting for home-care providers can help to monitor the rising cost of assistance and confirm the cost effectiveness of this type of care.