Abstract: A heatsink assembly with an adjustable retaining clip is provided. A heatsink member is retained in flush communication with an electronic device package by securing a retaining clip over the heatsink member into communication with the marginal portions of the electronic device package. An adjustment member is provided through the top wall of the retaining clip to adjustably control the pressure and tension of the flush communication between the heatsink member and the electronic device package. A channel in the heatsink member may be provided for recessed installation of the retaining clip to permit unrestricted installation of a fan on the top of the heatsink.