Purpose: to evaluate the usefulness of intraoperative radiofrequency thermoablation of liver tumours in association or not with hepatic resection. Materials and methods: 21 patients were treated between January 1998 and December 2001, there were 4 hepatocellular carcinoma and 17 metastasis. In 13 cases radiofrequency was associated to hepatectomy, in 3 cases to resection of extraepatic disease and in 5 cases were performed alone. 23 lesions were treated by radiofrequency (range 13); the mean dimension was 26 millimetres (range 8-70). A clamping of the liver pedicle was always done. Results: there were no operative deaths, 3 (14.3%) patients developed complications related to radiofrequency (2 biliary leakages, 1 hepatic abscess). 14 (66.7%) patients were alive after a mean follow up of 14.5 months, 2 of all (9.5%) had a recurrence in the site previously treated with thermoablation. Association between hepatectomy and radiofrequency increased the number of curative liver resections from 10.1% to 16.3% (in case of colorectal metastasis). Discussion: intraoperative radiofrequency is useful to increase the number of curative hepatectomies, to treat liver masses which demonstrate unresectable or found by ultrasonography at the operating time and even to reach tumours difficult to manage by percutaneous approach. In any case the aim is to obtain the absence of macroscopic neoplastic disease (R0 status). It is a safe and effective therapeutic strategy, anyway all procedures and indications are still not completely cleared. Conclusions: Intraoperative thermoablation of liver tumour is safe and effective and increases therapeutic the number of curative hepatectomies. Further progresses may improve the efficacy and extend the indications of this strategy.