This chapter contains sections titled: Introduction Control of Particle Size Key Issues in Organic Reactive Crystallization Scale-up Example 10-1 Reactive Crystallization of an API Example 10-2 Reactive Crystallization of an Intermediate Example 10-3 Reactive Crystallization of a Sodium Salt of an API Example 10-4 Reactive Crystallization of an API Creation of Fine Particles—In-Line Reactive Crystallization