An intraocular lens injection instrument (1) for injecting an intraocular lens (100) into a patients eye includes: a cylindrical hollow injection part (20) formed with a passage (20b) of which an inner diameter gradually decreases toward a tip end (20a) a push member (12) configured to push an outer circumferential portion of the intraocular lens to fold the intraocular lens in the passage of the injection part so that the intraocular lens is pushed out of the injection part from the tip end of the injection part a guide portion (36) for guiding a push-out direction of the push member a first protrusion (38) constituting one side wall surface of the guide portion and a second protrusion (40) constituting the other side wall surface of the guide portion. In pushing out the intraocular lens by the push member, while a rear support part (112B) placed closer to the push member has a distal end portion (118B) positioned closer to the first protrusion and has a root portion (116B) positioned closer to the second protrusion, the rear support part is folded inwardly in the outer circumferential portion of the optical part, and the first protrusion and the second protrusion are shaped asymmetry.