An oblong diaphragm valve has curved surfaces carved into faces of a body and a plate. The curved surfaces have an oblong shape and define an oval or egg-shaped valve chamber when the body and the plate are joined and secured to each other, with a diaphragm sandwiched there-between. An inlet and an outlet are defined in the curved surface of the body at opposite ends defined by a length of the valve chamber. A flow passage is defined in the curved surface of the plate and has an opening centrally located relative to the valve chamber for actuation of the diaphragm to close or open the oblong diaphragm valve with minimal or no stress, ensuring durability and longevity of the oblong diaphragm valve with increased precision, while reducing fluid waste and pressure spikes in pumping operations.