A medical insertion aid for surgical instruments and/or optical systems includes a shank forming an insertion duct, at the inner wall of which at least one groove extending in the longitudinal duct direction or being longitudinally orientated is formed. In addition or as an alternative, a medical insertion aid includes a distal end portion (axial central portion preferably in the distal end area) and a radially outwardly extending, preferably closed peripheral fluid flow inhibiting edge in the distal end portion. The inhibiting edge preferably forms at least one axially opening circular channel or groove, with the opening being directed distally and/or proximally.
