A predictive model is developed for the filtration of noncoagulating particles in packed-bed depth filters. The model uses the trajectory analysis results of Rajagopalan and Tien (1976, A.I.Ch.E. J. 22, 523-533) to calculate initial collection efficiencies of the granular media. Stochastic simulations of particle deposition are used to predict the decrease in collection efficiency that results from deposited particles not only occupying sites on the collector but also shadowing large deposition areas. A comparison of model predictions with data obtained from batch latex filtration experiments showed qualitative but not quantitative agreement. The observed decrease in collection efficiency could be described by a simple empirical expression, characterized by a single shadowing exponent, that was first suggested by Terranova and Burns (1991, Biotechnol. Bioengng 37, 110-120). By developing a correlation for the shadowing exponent from the stochastic simulations and adjusting the expression for the initial collection efficiency, reasonably accurate model predictions could be made once the model parameters from a single experiment were determined. A study of the effect of dimensionless model parameters on predicted breakthrough curves showed that the optimal operating conditions to filter a given liquid suspension occur when the ratio of the particle-to-collector diameter is maximized. An approximate analytical solution is also developed to predict breakthrough behavior in lieu of a numerical solution.