A diffuser for a centrifugal compressor including an annular diffuser housing having a plurality of diffuser flow passages therethrough the housing. Each passage including a throat portion and a diffusing section with upstream and downstream diffusing portions. A diffusing passage centerline includes a linear portion extending downstream through the throat portion and the upstream diffusing portion and a curved portion of the diffusing passage centerline extending downstream from the centerline linear portion through the downstream diffusing portion. The diffuser flow passages may have an equivalent cone angle varying non-linearly or more particularly curvilinearly downstream along curved portion. The downstream diffusing portion may be flared.