A mixer impeller having high efficiency blades. The impeller may include a central hub and a plurality of blades attached to and extending radially outwardly from the hub such that leading edges thereof are inclined upwardly from trailing edges thereof. Each of the blades may include a root attached to the hub, a tip, a first crease extending along substantially an entire length of the blade dividing the blade into a leading portion and a trailing portion, the leading and trailing portions meeting at the first crease such that the leading portion is angled downwardly from the trailing portion, and a second crease extending from a portion of the leading edge of the leading portion between the root and the tip diagonally along the leading portion to the tip, the second crease intersecting the tip at a point spaced from a point where the first crease intersects the tip, the second crease forming a tip portion of the leading portion that needs a remainder of the leading portion such that the tip portion is angled downwardly from the leading portion.