The device, tool, instrument and the like, for patellar resurfacing, according to the invention, comprises at least one bearing framework (IN), which incorporates a cutting slot (Tpg) and a lower support guide (G2) which may assume different positions with respect to the centre of the patellar articular surface. The device is completed by an upper support guide (G1) of the patella for maintaining the shape-constraint coupling between the bearing framework and the patella. Advantageously the device uses the peripheral surface (and not the central one) of said patella, guaranteeing minimal invasiveness and perfect visibility.