A comprehensive model to predict the lead aerosol size distribution for typical incinerator operating conditions has been developed. Using the feed rate and incinerator operating conditions, the metal transfer rate to the gas phase is determined using a mass transfer calculation. A detailed, multicomponent aerosol dynamic model is developed accounting for the chemical kinetics and applied to a lead-oxygen-chlorine system. Reasonable agreement is obtained between model predictions and experimental data from controlled studies for different aspects of the model. The effect of chlorine on the resulting aerosol size distribution has been determined. The role of the transfer rates of lead to the gas phase on the resulting size distributions have also been determined. Simulations have been performed for typical conditions encountered in a waste incinerator.