This study investigated the discomfort glare produced by the high-brightness LED billboards in relation to four factors: flicker frequency, panel luminance, viewing angular sub-tense, and ambient illuminance. The results showed that visual comfort is not affected by ambient illuminance but by the other three factors. Also, interaction was found between luminance and viewing angle. The experimental data were curve fitted to construct visual comfort models of LED billboard displays. By modulating the operating conditions, comfort display with LED billboards can be achieved.