Literature values of independent measurements of dry deposition velocities are summarized as a function of particle diameter and gas speciation. In most of the experiments reported in the literature, there are uncertainties that have hindered the development of general predictive deposition velocity models. However, one model (Sehmel and Hodgson, 1978) offers a more useful approach for predicting particle dry deposition velocities as a function of particle diameter, friction velocity, aerodynamic surface roughness, and particle density.