Kinetic nucleation equations are solved numerically to determine the size distribution of small droplets formed in a supersaturated vapor. Decrease in supersaturation as a consequence of the phase transition process in a closed system is taken into account. Size distributions of nuclei at various initial supersaturations (changing from 3 to 5) are compared at the same real times for condensation of ethanol vapor. Increase in the initial supersaturation leads to the faster depletion of the mother phase and the growth of the largest droplets decelerates as a consequence of the decrease in supersaturation. The largest droplets are not formed at the highest initial supersaturations, as the standard nucleation theory predicts (under constant supersaturation), but at the initial supersaturation S(i) approximate to 4. (C) 2008 Elsevier Ltd. All rights reserved.