In this work, the operation of membrane-assisted seeded batch crystallization is modeled for five substances: potassium nitrate, potassium sulfate, pentaerythritol, succinic acid, and potassium alum. The effect of seed loading, seed size, and water removal rate on product crystal size is investigated. Seed loading and seed size were found to have a significant impact on product crystal size for a given batch time and product yield. Trajectories for the optimal water removal rate versus time were also determined. Overall, the results show that membrane-assisted crystallization behaves similarly to other types of crystallization in terms of product crystal size and size distribution while having the potential to reduce cost and equipment size.