Robotic surgical assembly (100) comprising a support (104), one macro-positioning arm (30), connected to said support (104) and having a plurality of degrees of freedom, said macro-positioning arm (30) comprising a support member (38), at least two micro-positioning devices (41, 141, 241, 341), each having a plurality of motorized degrees of freedom, connected in cascade to said support member (38) of said macro-positioning arm (30), and at least two medical instruments (60, 160, 260, 360), each is connected in cascade to each of said micro-positioning device and comprises a jointed device (70, 170, 270) having a plurality of motorized degrees of freedom including a plurality of rotational joints； and wherein each of said at least two medical instruments (60, 160, 260, 360) comprises a shaft (65), suitable for distancing said jointed device from said micro-positioning devices by a predetermined distance in a shaft direction (X-X).
