An LED lamp (10) includes a lamp base (100), an optical lens system (400), an LED (500) mounted in the optical lens system and a heat dissipation device (300) interconnecting the lamp base and the optical lens system. The heat dissipation device includes a heat sink (334) and a heat pipe (332). The heat sink includes a central block (3340), a plurality of fins (3342) mounted on an outer circumferential face of the central block and a receiving hole (3346) defined axially through the central block. The heat pipe is circumferentially retained in the receiving hole and in thermal contact with the LED.