AIM: To compare characteristics of preloaded and non-preloaded intraocular lens (IOL) delivery systems during IOL delivery procedures. METHODS: Total 101 human eyes were included in this prospective observational case series. Delivery characteristics of 5 types of IOLs including iSert250 NC60 (NC60), EnVista MX60 (MX60), AcrySof IQ SN60WF (SN60WF), TECNIS ZCB00 (ZCB00), and TECNIS PCB00 (PCB00) were investigated. NC60 and PCB00 were injected via preloaded delivery systems and other IOLs were injected via non-preloaded systems. In the human trial, time taken from IOL loading to completion of implantation was measured in all eyes undergoing conventional cataract surgery. Using 4 excised porcine eyes, dynamics of ophthalmic viscosurgical device (OVD) between an IOL injector and a porcine eye was analyzed using fluorescein sodium-stained OVD. RESULTS: The average time for IOL implantation was 22.0s for NC60, 43.2s for MX60, 32.3s for SN60WF, 41.4s for ZCB00, and 14.6s for PCB00 respectively. The number of cases with IOL manipulation with a second instrument was 6 for MX60, 2 for ZCB00, 0 for SN60WF, NC60, and PCB00. Amount of OVD pushed into a porcine eye was smaller with a preloaded system than with non-preloaded systems. CONCLUSION: IOL delivery with preloaded systems is faster and more predictable. Moreover, a preloaded delivery system shows relatively less OVD pushed into a porcine eye than non-preloaded systems.