The effect of glucose and its substitution by maltose on pigment production by Monascus purpureus 192F were studied in pH-controlled fermenter cultures using HPLC analysis to determine individual pigment concentrations. A maximum of five pigments were detected in fungal extracts. These were the yellow pigments, monascin and ankaflavin, the orange pigments rubropunctatin and monascorubrin, and the red pigment, monascorubramine. Monascorubramine was the major product in all cases. The use of maltose (50 g l-1) improved the production of monascorubramine, compared to glucose cultures, especially when peptone was the nitrogren source. At a carbon source concentration of 50 g l(-1), large amounts of ethanol were produced by the fungus, despite aeration, which suggested that respirofermentative metabolism was occurring. Subsequent use of a low initial glucose concentration (20 g l(-1)) in batch culture, or fed-batch culture with glucose feeding, resulted in minimal production of ethanol and high monascorubramine concentrations. These conditions also favored production of the orange analogue, menascorubrin, whereas ankaflavin was favored at high glucose concentrations.