Silicon Nanowire Fin Field Effect Transistor (SiNWFinFET) is a unique transistor in which all of its gates wrap the insulator and inner layer of silicon. In this paper, the effective channel length effect on Silicon Nanowire FinFET is presented, based on the quantum confinement effects. The analytical model of current–voltage incorporated with the effects of channel length modulation, is developed, and verified with published experimental data. The results show that by considering the channel length modulation effect, the SiNWFinFET performance is improved. Results obtained demonstrate the importance of considering the effective channel length in SiNWFinFET devices. Carrier mobility improvement based on the current–voltage graph is also reported.