Three fundamental principals associated with aquatic therapy differentiate it with respect to exercise on land, and in air. These are buoyancy (reduction in weight of the body within the buoyant medium of water), viscosity (a "drag force" is generated when moving within water, when compared with the same movement in air), and the thermodynamic aspect of water exercise, during which the heat capacity of water is about 1000 times greater than that of an equivalent amount of air; equating to a heat transfer from the body into water at a rate 25 times faster than that of air. Aquatic conditioning, can improve neurologic functioning, with dividends favorably impacting activities of daily living, health maintenance, safety, and ultimately quality of life. Here, we review the application of aquatic exercise training in MS patients.