Colloid-colloid interactions have been largely neglected in the past studies of particle deposition in porous media. Except for the complexity involved in accounting for such interactions, this neglect may largely result from limitations of classic filtration theories, which predict no attachment under unfavorable surface interactions (i.e., in the presence of repulsive energy barriers to deposition due to like-charged surfaces). Recent advances in understanding the mechanisms of colloidal deposition in the presence of energy barriers (e.g., wedging at grain-grain contacts and retention in secondary energy minima) provide a basis for inclusion of colloid-colloid interactions in predictions of particle deposition. Here, effects of colloid-colloid interactions on particle retention in porous media are investigated through a Lagrangian particle trajectory model that has been parallelized to allow particle-particle interaction. Results show that despite their mutual electrostatic repulsion, colloid-colloid interactions can mitigate or enhance retention in porous media depending on the fluid velocity and chemical conditions. In addition, parameters characterizing repulsive colloidal interactions, pore geometry are explored in developing a correlation equation for predicting particle deposition in porous media in the presence of energy barriers.