The planar lighting device includes a pair of light sources, a light guide plate and a housing. The light guide plate is disposed between the light sources and includes a light exit plane and a pair of opposite light entrance planes respectively provided opposite to the light sources. The planar lighting device thus configured features a heat dissipation structure whereby a heat sink is connected to each of the light sources and heat pipes are attached to the heat sink so as to extend toward the center of the housing. Disclosed is a thin and lightweight planar lighting device suitably used for a large display television or the like, capable of emitting illumination light free from brightness unevenness or with a reduced level of brightness unevenness, allowing increase of dimensions of the display area, and capable of optimally releasing heat generated by the light sources.