A composite anoscope for ano-rectal diagnostic and surgery, wherein the anoscope (2) also comprises an internal component (1), to be inserted therein, and a suitably shorter external component (3), ending with a conic frustum mantle (18), wherein the anoscope (2) is to be inserted. The three components (1, 2, 3) are all conic frustum shaped hollow bodies having circular cross-section. The internal component (1), when inserted in the anoscope (2), forms therewith a single body having a compact and smooth external surface and an ogival tip. The external component (3) is provided close to its mouth with slotted wings (19, 20), to be fixed to the perianal skin for securing the whole composite anoscope during the diagnostic and surgical operations.