The growth kinetics of III–V semiconductor nanowires by a vapor–liquid–solid method is theoretically analyzed. The analysis includes three concurrent processes—the deposition rate of an element of group V, penetration of atoms of group III into the droplet taking into account surface diffusion, and nucleation at the liquid–solid interface. A generalized formula for the vertical growth rate of nanowires is obtained, and it can be limited by one of the three processes. Various growth conditions with Au and Ga catalysts depending on the fluxes of elements of groups III and V and the nanowire radius are analyzed.