Field emission (FE) properties of diamond coated tungsten tips have been studied using a glass FE microscope. Diamond film was deposited on a tungsten field emitter by hot filament chemical vapour deposition method. Stable emission was found to occur from discrete locations as seen from the FE patterns. FE current-voltage (I-V) characteristics at 300 and 78 K have been studied. The difference in I-V characteristics at 300 and 78 K has been attributed to the reduction in conductivity at 78 K. The emission current is found remarkably stable over a long period of more than 3 h. Spectral analysis of the FE current shows noise proportional to 1/f(0.35), f being the frequency. The overall behaviour of the diamond coated tungsten emitter is consistent with the subband model of electron emission from semiconducting diamond.