The possibility of producing single cell protein (SCP) from shochu distillery wastewater by Aspergillus awamori var. kawachi has been examined. A yield of about 40 g/l of biomass, about 40% of which was protein, was obtained from a 24-h jar-fermenter culture. The yield of biomass from shochu distillery wastewater, calculated on the basis of organic matter content, was about 40%. Digestibility, as determined by digestion with pepsin, was only about 52% without pretreatment, but this value increased to 62% after heating the biomass at 100 degrees C for 20 min. Cultivation of the fungus was also suitable as a treatment for shochu distillery wastewater since solid matter was degraded and the separation of liquids and solids was facilitated.