A bipolar device (1) for the surgical resection of tissues, comprising two insulated and electrically conductive filaments (2, 3), which have a relative proximal extremity (2a, 3a) and a relative distal extremity (2b, 3b), where the distal extremities (2b, 3b) are connected together by means of insulating means (4) to define a loop (5) intended to accommodate the portion of tissue to be re- sectioned, where each of the filaments (2, 3) has a relative uncovered section (12, 13), of which a first section (12) and a second section (13), having a limited extension and suitable for acting as a positive electrode and a negative electrode respectively, in such a way that between them an electric discharge occurs for the resection of the tissue inserted inside the loop (5) and placed between the electrodes themselves, at least a tubular element (6) inside which both the filaments (2, 3) are inserted sliding, the loop (5) being suitable for opening and closing by effect of the sliding of the filaments inside the tubular element (6), connection means (7) for electrically connecting the filaments to a bipolar current source, where the first section (12) has an extension between 3 mm and 8mm and the second section (13) has an extension between 15mm and 25mm.