The nuclear magnetic resonance has been studied in single crystal magnesium at 4.2 °K. The measured values for the Knight shift and quadrupolar interaction are K = (0.1127 ± 0.0005)%, K′ = (0.0004 ± 0.0002)%, e2qQ/h = 324 ± 6 kc/s. Comparison with the results of Rowland reveals the Knight shift to be independent of temperature in direct contrast to the behavior of cadmium, but the quadrupole interaction is strongly temperature dependent.