Velocity of sound measurements have been made in superheated steam at pressures from 200 to 1000 lb/in.2and over a range of temperatures from 395° to 750°F. Experimental values are in agreement with calculated values, using existing Tables on the thermodynamic properties of steam. A variable path‐type acoustic interferometer of stainless and chrome‐alloy steel was used for the present work. Frequency range was from 650 to 1000 kc/sec.