In the direct hydrolysis of elemental sulfur, immediate precipitation of the sulfide as the copper salt allows measurement of the initial sulfur isotopic compositions of product sulfide and sulfate. δ34S values for product sulfide and sulfate and for parent elemental sulfur at reaction temperatures of 50 to 200°C differ by less than 3‰ and demonstrate that only minor sulfur isotope fractionation accompanies hydrolysis. These data suggest that the larger values commonly reported reflect, not hydrolysis reactions, but other secondary equilibration processes.