With a view to determine the minimum thickness of shielding required for a neutron generator, the absorption characteristics of various materials were measured for neutrons produced through the T(d,n)4He and D(d,n)3He reactions. The shielding thickness required to reduce the transmitted dose to permissible levels of exposure was found to be determined by the reduction of the dose rate of the 15 MeV neutrons. Since the shielding is required for the protection of the operating personnel, the quantity of interest is the dose equivalent. This quantity was measured with a neutron rem detector for various shielding materials as a function of the shielding thickness. Attenuation curves are reported for water, concrete, paraffin and borated laminated wood. After the final shielding of the neutron generator was constructed, the radiation levels outside the shield were found to be below the maximum permissible values, as indicated by the instrumentation used.