Abstract: A hydrotherapy spa includes an upwardly open, U-shaped, cross-sectional, waterproof spa shell defining a receptacle for holding water. The spa shell includes a horizontal seat portion and an integral seat back extending generally vertically upwardly therefrom. A water supply manifold is sealably mounted to the exterior of the spa shell, is spaced therefrom and forms a manifold chamber, with the supply manifold overlying a portion of the seat and the seat back. A plurality of small diameter apertures are formed in the spa shell opening to the manifold chamber. Water under pressure is circulated from the interior of the spa shell to an inlet port opening to the manifold chamber. The water is discharged through the small diameter apertures into the interior of the spa shell and against the back and buttocks of an occupant within the seat area seated at a hydrotherapy seat defined by the supply manifold and the seat and seat back of the spa shell which include the small diameter apertures.