Complete tumour cell death is necessary for any ablative technique to be successful. Microwave tissue ablation (MTA), radiofrequency (RF) and cryotherapy (CT) are three methods of destroying liver tumours in situ. Unlike MTA, RF and CT rely on conduction of the thermal insult for their cytotoxicity, potentially affecting lesion uniformity. The aim of this study was to compare the uniformity of demarcation of lesions induced by MTA, RF and CT in the rat liver.