A heat dissipation unit includes a heat pipe and a base seat. The base seat has a first side and a second side. The second side is formed with a channel and multiple perforations in communication with the first and second sides. The heat pipe has a heat absorption section and a conduction section. The conduction section extends from the heat absorption section in a direction to at least one end of the heat pipe distal from the heat absorption section. Several parts of the heat pipe corresponding to the perforations are received in the perforations and flush with the first side of the base seat. The heat dissipation unit improves the shortcoming of the conventional heat dissipation component that the coplanar precision between the heat pipe and the protruding platform of the base seat is hard to control.