An experimental study on the performance of a flat-plate heat pipe was conducted by measuring the surface temperature distribution using thermochromic liquid crystals (TLC). Single wide-band liquid crystals were coated on the heat pipe and the colors exhibited by the liquid crystals were captured using a color video camera and calibrated using thermocouples. Comparative experiments were performed on the heat pipe and a heat pipe shell (without working fluid) under steady state and transient conditions. The full-field temperature visualization revealed a number of hot spots in the condenser section under both steady state and transient operation conditions. These hot spots are caused by non-uniformity in the wick structure of the heat pipe.