A method for the analysis of hydrogen in uranium metal by mass spectrometry is described. The samples are introduced into a tube containing helium at atmospheric pressure. Hydrogen gas evolved from the heated sample is mixed with a helium gas stream flowing through the tube and over the sample at a constant rate. The effluent gas mixture is monitored at M/e 2. The resulting rate-of-evolution curve is integrated with respect to time by an electronic integrator. The empirical number so obtained is directly proportional to the hydrogen content of the metal. The method has been adapted to the Bendix Time-of-Flight and the Consolidated Electrodynamics Model 21-611 Mass Spectrometers. A description of the associated instrumentation is presented. The determination requires from 3 to 10 min. on the mass spectrometer, depending on the size of sample and the hydrogen content of the metal. Precision comparable to that of the classical vacuum technique is obtained. The technique described is also adaptable to the study of hydrogen diffusion through uranium metal.