Two methods were investigated for desulfurizing coal by treatment with FeCl3. One method involved treating coal with a molten mixture of FeCl3 and NaCl at 200 degrees C. Another method involved treating coal with dry, unfused FeCl3 at 200-300 degrees C. Both methods were found to reduce greatly the sulfur content of different types of bituminous coals. The degree of desulfurization was observed to be strongly dependent on the FeCl3: coal ratio, increasing as the ratio increased. However, these treatments also reduced the heating value of the coal and increased its chlorine content. The treatment with unfused FeCl3 proved superior to the treatment with the molten mixture in some respects because a higher desulfurization was achieved and less chlorine was added to the coal.