The liquid‐liquid extraction of an extracellular alkaline protease from its fermentation broth was carried out, using a reversed micellar organic solvent. Optimum process parameters were determined for extraction using a 250 mM AOT in isooctane micellar solution. With unequal phase volume ratios, purification factors as high as 6 have been obtained from completely untreated broth. Yields up to 56% were achieved from the same broth using a three‐stage cascade.