Hepatocellular carcinoma is one of the most common malignancies in the world, with the liver being the second most frequently involved organ in metastatic disease. Although the gold standard treatment for malignant liver disease is surgical resection, only few patients can undergo such an intervention. This explains the current great interest in various loco-regional therapies, of which radiofrequency thermal ablation (RFA) is the most common. To date, only a few studies have evaluated the complications associated with this treatment. The aim of this study was to determine the rate of complications, divided into major and minor, in patients treated with RFA. A total of 373 hepatic lesions in 250 patients were treated with 292 sessions of percutaneous ultrasound-guided RFA. According to our data, ten patients (4%) had major, complications, twelve patients (4.8%) had minor complications, no deaths occurred. Around 30% of patients had a body temperature increase of up to 38 'C. All complications, except one, were treated with nonsurgical therapies. One patient with massive hemoperitoneum required surgery. In conclusion, percutaneous RFA is a loco-regional therapy associated with a low incidence of side-effects and a negligible risk of death.