This study was designed to evaluate the enlargement of incision sizes before and after intraocular lens (IOL) implantation in coaxial microincision cataract surgery.　　The operation was performed on 138 eyes. NY-60 IOL was implanted with N18 cartridge, SN60WF and ZCB00 implanted with D cartridge, SN60AT implanted with C cartridge.　 Incision sizes (mean±SD) after IOL implantation of NY-60 were 2.33±0.05 (2.2mm corneal incision), 2.30±0.00 (2.1mm corneal incision), 2.26±0.05 (2.0mm corneal incision) and 2.24±0.05 (1.9mm corneal incision), SN60AT were 2.34±0.05 (2.2mm corneal incision) and 2.43±0.05 (2.2mm sclero-corneal incision), SN60WF were 2.34±0.05 (2.2mm corneal incision), 2.29±0.04 (2.1mm corneal incision), 2.20±0.00 (2.0mm corneal incision) and 2.11±0.04 (1.9mm corneal incision), ZCB00 were 2.33±0.05 (2.2mm corneal incision), 2.27±0.05 (2.1mm corneal incision), 2.33±0.05 (2.1mm sclero-corneal incision) and 2.29±0.04 (2.0mm sclero-corneal incision).　　Incision sizes were enlarged after implantation of IOLs in all cases. The incision sizes the IOL manufacturer recommended were not stress-free size during IOL implantation.