The results of 79 liver resections performed in the period January 1972 to May 1987 are described with emphasis on the role of intraoperative ultrasonography and ultrasonic liver parenchyma dissection. The aim of this study is to see whether these adjunctive techniques are able to lower mortality and morbidity. Resections were done for benign disease (44 patients) or malignancy (35 patients). In these patients, 24 major and 55 minor liver resections were performed. Six of these patients (7.6%) died within 30 days after the operation. In one-third of the patients, complications occurred. In 25 of the 79 resections, intraoperative ultrasonography and ultrasonic liver dissection were used. Intraoperative ultrasonography changed the planned resection in eight patients. No statistically significant difference in morbidity and mortality could be found in patients operated with ultrasonic dissection, compared to patients with conventional dissection techniques. From this study, we conclude that intraoperative ultrasonography is a useful adjunct in liver surgery.