Abstract: A portable log splitting apparatus is provided with a power source and a controllable drive system for selectively drivingly coupling the power source to a rotatable, screw-shaped wedge. The wedge has a complexly tapered, substantially conically shaped outer surface which extends from a pointed forward end to an enlarged diameter base. Threads are formed on the outer surface. A log or log portion to be split is positioned adjacent the pointed end of the wedge and, as the wedge rotates, its threads draw the log or log portion onto progressively larger diameter portions of the wedge, causing the log or log portion to split apart. One feature of the invention lies in the complexly tapered character of the outer surface of the wedge which, in comparison with prior uniformly tapered log splitting wedges, provides an improved splitting action, prevents logs from becoming "hung-up" on base portions of the wedge, and provides a reduction in friction forces encountered between the wedge and a log being split.