Between 1982 and 1990 major liver resections were carried out in 28 patients, in 14 with the conventional technique, in 14 with the Cavitron ultrasonic surgical aspirator (CUSA) dissection device. The patients in the CUSA group were older and had more often multiple metastases. Peroperative blood loss, duration of operations, postoperative morbidity and mortality, ICU stay and overally hospital stay were all reduced in the CUSA group; for peroperative blood loss (p less than 0.05) and duration of operation (p less than 0.01) the reduction was statistically significant. The use of CUSA has contributed to the increased safety of liver resections.