Itaconic acid production by Aspergillus terreus TN-484 from corn starch as a carbon source was investigated. The production medium consisted only of corn starch pretreated by partial hydrolysis with nitric acid at pH 2 before autoclaving at 121 degrees C for 20 min. Higher than 60 g/l of itaconic acid was produced by A. terreus TN-484 in hash fermentation from medium consisting of 140 g/l of corn starch and no nitrogen source or other ingredients. The yield of itaconic acid based on the amount of corn starch consumed was higher than 50%, and the yield was similar to that of crystal glucose. The yield obtained in flask fermentation was successfully reproduced in a 2.5-l air-lift bioreactor.