Fluid velocity local to the dissolving surface will affect the dissolution rate. It is difficult to anticipate what local fluid velocities are present within compendial dissolution apparatuses from set flow rates or stirring rates. A range of qualitative and quantitative velocimetric techniques are available to assess and characterize hydrodynamics. These methods are frequently used in combination with computational fluid dynamics simulations to characterize and simulate hydrodynamics. Dosage form location and motion varies between apparatuses, and the presence of the dosage form itself can impact local hydrodynamics. Each apparatus described has identified hydrodynamic features which may also vary with agitation rate. This review describes the methods used to simulate and characterize hydrodynamics and summarizes some of the main findings from studies investigating hydrodynamics in the paddle, basket, and flowthrough dissolution apparatuses.