A process is disclosed for removing heavy metals from a hydrocarbon gas stream by contacting the hydrocarbon gas stream, which contains a heavy metal and less than 10 ppm oxidizing compounds, with a composition containing a molecular sieve and sulfur resulting in a treated stream containing less heavy metal than the hydrocarbon gas stream; wherein the molecular sieve contains alumina, silica, and iron, and optionally copper and zinc. Optionally, the hydrocarbon gas stream can also contain a sulfur compound.