This paper reports the thermal performance of a high-brightness light-emitting diode (LED) array package with a novel placement method on a printed circuit board (PCB). The precise heat transfer analysis and modeling using computational fluid dynamics (CFD) were performed according to the practical working conditions of the LED array. Emphasis was placed upon investigating how the temperature of the surface of LEDs changed in accordance with different placement methods. A significant drop in the surface temperature of the LEDs was found when the triangular and arithmetic spacing placement methods were used; hence, the overall heat dissipating capability of the LED array to the PCB was improved. By optimizing the placement design, the average surface temperature of the LED array achieved a decrease of about 20%, from to . The illuminance level of each placement design was measured and compared. Both CFD simulation and experimental results are provided to demonstrate the efficacy of the proposed approach for LED array thermal management.