Light emitting diodes (LEDs) are normally operated at high current levels resulting in substantial junction heating. However, the junction temperature cannot be measured directly. In the study reported here, it was estimated junction temperature in LEDs with peak emission 400 nm. Temperature was estimated from current-voltage (I-V) measurements as a function temperature and peak-shift of optical emission spectra with increasing temperature. For a diode operated at a current-level of 100 mA, a temperature of 100 o C was estimate from current voltage measurement and 160 o C from the peak-shift in the optical emission spectra. The difference in temperature estimated using the two different technique is not understood at this point. Mater. Res. Soc. Symp. Proc. Vol. 955