Sodium soap of dihydroxystearic acid (DHSA) was prepared by reacting DHSA and sodium hydroxide (NaOH). The properties of the soap, such as foamability, detergency, biodegradability and wetting power were evaluated. DHSA soap had higher foamability and detergency than stearic acid soap, comparable to palm stearin sulphonated methyl ester (SME) at room temperature. DHSA soap degraded more than 60% in 28 days, but stearic acid soap only 30%. The wetting time for DHSA soap was 2 min, comparable to SME but faster than stearic acid soap. DHSA soap also exhibited good corrosion inhibition with a corrosion rate of 0.002 mm yr^-1 at 100 ppm