A heat dissipation assembly for dissipating heat generated by an electronic component includes a heat sink contacting the electronic component, a pair of retaining members fixed on two lateral sides of a top portion of the heat sink, a pair of arms pivotably secured to the retaining members, and an operating member pivotably attached to the retaining members. The operating member has two cams for interacting with the retaining member and the heat sink. When the operating member is rotated from a vertical orientation to a horizontal orientation, the arms are driven by the operating member to rotate towards the heat sink to engage with barbs of a retention module. Furthermore, the arms are also activated to move upwardly so they can tightly engage with the barbs, thereby securing the heat sink to the electronic component.