A heat sink and mounting bracket arrangement includes a radiation fin module including a stack of radiation fins and an insertion hole located in one end of the stack of radiation fins, and a mounting bracket made from a metal plate sheet by stamping and including a bottom panel clamped on a bottom wall of the stack of radiation fins, an angled mounting panel rearwardly extending from one end of the bottom panel, a mounting slot cut through opposing top and bottom surfaces of the mounting panel for the mounting of a fastening member to affix the mounting bracket to an external substrate, and an angled plug plate forwardly extending from the bottom panel and tightly press-fitted into the insertion hole of the radiation fin module.