The first report of rupture of the stomach due to diathermy-elicited gas explosion during gastrotomy in a patient with intestinal ischemia resulting in obstruction and jejunal and gastric dilatation is presented. In the obstructed stomach or small bowel, a proliferation of hydrogen- and methane-producing bacteria can occur, leading to the accumulation of these combustible gases in explosive concentrations. In cases of gastrointestinal tract obstruction, the diathermy knife should not be used in entering the gastrointestinal lumen.