An electrode pattern design methodology that improves the current uniformity in mesa-structured GaN/InGaN blue light-emitting diodes (LEDs) is investigated. Comparisons between an LED with a new electrode pattern adopting the proposed methodology and an LED with a commercially used electrode are made in view of both current and luminance distributions. Simulations as well as experimental results show that the proposed simple design methodology is very effective to spread current more uniformly in the active layer.