From the distillation process after butanol fermentation, wastewaters mainly consisted of organic acids and residual sugars and with high COD (usually >20,000 mg/L) are generated. Without any pretreatment and adding other nutrients (nitrogen sources and trace elements), these wastewaters were used as substrate for microbial oil production by oleaginous yeast Trichosporon coremiiforme. After 5 days' lipid fermentation, all the sugars and organic acids measured were totally utilized by T. coremiiforme and a 68% of COD degradation could be obtained. The highest biomass and lipid content of T. coremiiforme on the wastewaters were 5.8 g/L and 19.1%, respectively. This work shows that T. coremiiforme is a promising strain for microbial oil production on the wastewaters after butanol fermentation. (C) 2012 Elsevier Ltd. All rights reserved.