• To present a novel method of renal ablation using direct current electrolysis, using a porcine model to assess the safety and efficacy of the technique. • In all, 20 anaesthetised pigs were used, after receiving ethical approval. The pigs were housed and managed in accordance with Institute of Medical and Veterinary Science guidelines. • A single 6 F catheter incorporating cathode and anode was inserted directly into the renal parenchyma via a loin incision. A direct current of 100 mA was applied for varying times. • Several treatments were performed in each pig and a total of 72 treatments were analysed. • The pigs were recovered and observed for 3 days with an analysis of electrolytes and creatinine after ablation. The pigs were humanely killed at 3 days and the kidneys submitted for histological analysis. • Complete tissue destruction was seen in the area of kidney treated with no viable cells. • A sharp line of demarcation was noted between normal renal parenchyma and the area of coagulative necrosis. The area of tissue ablation was reliably predicted from the duration of application of the electrolytic current. • One pig developed a secondary haemorrhage. • Renal electrolysis is a new method of focal renal ablation. The procedure may be carried out using a fine ablation catheter (6 F) allowing for the development of minimal intervention treatment of small renal masses. • This study shows the technique to be effective and safe. As with other renal ablative techniques there is a small risk of postoperative haemorrhage.