A post support device that enables a rotted base portion of a wooden support post to be removed in situ and the remaining end of the support post to be secured for regained structural integrity, the device having a base adapted to being attached to the surface, elevation support means in cooperation with the base for supporting the post above the base, at least two cover plates, each adapted to covering a portion of the exterior of the post, and each including an elongate flange facing inward towards the post and generally transverse to the longitudinal axis of the post, said flange portion including a leading cutting edge to enable the flange portion to bite into the surface material of the post upon the application of force to the flange to provide a mechanical seal between the flange and the post, first and second fastening means for securing each cover plate to the post and the base and the elevation support means to the post or the filler block if one is used, respectively.