Light-emitting diodes operating on alternating current are gaining popularity in the LED industry, especially for lighting applications. Because junction temperature is a good predictor of LED performance, the availability of a method to accurately estimate the junction temperature of AC LEDs would be very useful. This study investigated a method in which a low reference current having a pulse width of less than several milliseconds was applied and the corresponding voltage across the device was measured and correlated to the junction temperature. Laboratory experiment data showed that the proposed method is a promising candidate for estimating AC LED junction temperature.