We present results on enhancement of 460 nm blue and 340 nm UV optical power output in III-nitride light emitting diodes (LEDs) using photonic crystals (PCs) under current injection. Triangular arrays of the PCs with diameter/periodicity of 300/700 nm were patterned using electron-beam lithography and inductively coupled plasma dry etching. The total power at 20 mA of 300×300 μm2 unpackaged LED chips revealed an increase by 63% and 95% for the blue and UV LEDs, respectively, as a result of the PC formation. Possible ways for further improving enhancement of light extraction using PCs are discussed.