Nuclear magnetic resonance measurements of the n, 1 1 9 Sn, l 2 7 Al Knight shifts and the n, 1 1 9 Sn, l 2 7 Al and H 1 spin-lattice relaxation rates in the A15-type compounds Nb 3 SnH x (D x ) (x = 0, 0.7 and 1.2) and Nb 3 AlH x (x = 0, 2.3) have been performed over the temperature range 10-460K. The low temperature n 1 1 9 Sn Knight shift and spin-lattice relaxation data indicate that in Nb 3 SnH x (D x ) the density of electron states at the Fermi level decreases strongly with increasing x. The hydrogen mobility in Nb 3 Al is found to be much higher than that in Nb 3 Sn. The behaviour of the proton spin-lattice relaxation rate for Nb 3 AlH 2 . 3 in a wide range of resonance frequencies (9-90 MHz) can be described by the model using a double-peak distribution of activation energies.