A heat dissipation device for electronic devices on a substrate comprises a base contacting one of the electronic devices for absorbing heat therefrom. A plurality of fins arranged on the base for dissipating heat. A plurality of airflow channels is defined between the fins, and each channel defines an intake and an outlet. A fan is located adjacent to the intakes and provides airflow entering the channels through the intakes and leaving the channels through the outlets. A first guiding member is located adjacent to the outlets. The airflow out of the outlets is guided, by the first guiding member, to be deflected towards the substrate for cooling other electronic devices neighboring the one contacting with the base.