The attenuation and speed of sound at 11 Mc were measured in pureN2over the pressure range 760 to 1 mm Hg using apparatus previously described. The excess attenuation in the nondispersive (low‐frequency/pressure) region as obtained from 70 measurements made between 80 and 760 mm Hg is(35.88 ± 0.04%)corresponding to a relaxation number of 5.26 collisions. The results will be compared with those of other investigators.