Silicon field emitters were coated with polycrystalline diamond using the hot-filament chemical vapor deposition technique. Maximum emission currents of 300-500 mu A were achieved from single-tip emitters. Current fluctuations have been found to be between 3% and 16%. Temporal dependence of emission current was studied over 36 h at initial current of 100 mu A. At the end of the testing, the current had decreased by 20%. Diamond-coated silicon emitters demonstrated favorable emission properties, as compared with uncoated silicon emitters.