A double suction impeller is disclosed. In at least one embodiment, the impeller is configured for centrifugal pumps and hydraulic power recovery turbines. The impeller's flow-path arrangement comprises inter-blade channels, intersecting each other at the impeller's outer diameter and defining a variable cross section shape, so that the equivalent number of blades is at least doubled with respect to a conventional configuration obtained by the coupling of two single suction impellers and an improved control over the velocity of the flow within the inter-blade channels is achieved.