The self-association of sodium n-hexyl sulfate (SHS) in aqueous solution has been examined at 25.0 and 35.0 degrees C. The critical micellar concentration (cmc) and the degree of counterion binding, beta, were determined by conductivity measurements at 25.0 degrees C. Both quantities were used to calculate the standard Gibbs energy change on micellization. The standard enthalpy change on aggregation was measured by microcalorimetry at the same temperature. Good agreement has been found when comparing with the properties of other sodium alkyl sulfates. Densities were measured at the same temperatures. The apparent molal volumes and partial molal volumes have been evaluated at concentrations above and below the cmc. The change in partial molal volumes in the formation of micelles has been evaluated from these measurements. Ultrasound velocity measurements were used to obtain the cmc in water. Apparent adiabatic compressibilities were calculated from a combination of density and ultrasound velocity measurements. Surface tension was measured at a temperature of 25.0 degrees C. Surface properties were calculated from these data.