Abstract: An inducer for vertical flow, cryogenic liquid centrifugal pumps comprising a stationary outer housing portion having an inlet and an outlet, the inlet located at a lower end and the outlet located at an upper end, the housing further having an inner wall portion with one or more spiral vanes projecting outwardly from the inner wall portion, the one or more spiral vanes defining one or more gap regions on the inner wall portion that spiral in a first direction, and an inner rotating impeller mounted on a rotating center shaft, the impeller having at least one curved blade which defines a curved, helicoid plane surface in which the slope of the plane increases as the distance from the center axis increases, the impeller rotating in a second direction which is in counter rotation to the first direction.