In a prospective study 60 patients underwent liver resection. Two different resection techniques, ultrasonic aspirator (CUSA, n = 30) and Jet-Cutter (n = 30), were compared, Speed of resection, blood loss, transfusion rate, liver hilus clamping time and tissue damage were evaluated on the basis of the area of transsected liver. Liver resection with the Jet-Cutter was significantly faster with a resection time of 0.35 min/cm2 in comparison to the CUSA (0.77 min/cm2, p < 0.001) and associated with less blood loss of 18.4 ml/cm2 (p < 0.05) than the CUSA technique (34.4 ml/cm2). Tissue damage in respect to levels of transaminases SGOT and SGPT was comparable with both techniques. The Jet-Cutter is a promising new instrument in liver surgery, and challenged by these results we used the Jet-Cutter in 7 patients performing laparoscopic liver resections.