A manual cement mixer having a mixing box with an open top, generally planar front side and rear side panels, and arcuate, parabolically curved, right and left sides forming left and right arcuate troughs, and a medial trough disposed therebetween, the troughs defining a mixing volume; a base frame for supporting said mixing box; and pivoting means for mounting said mixing box on said base frame and for manually inducing oscillations in said mixing box.