Production of cyclomaltodextrin glucanotransferase (CGTase) from Bacilus firmus was optimized in shake flasks using a statistical experimental design approach. Two level complete factorial designs in three variables were used for media optimization. The maximum CGTase activity obtained was 7.05 U ml(-1) with 21 g l(-1) corn starch, 22.6 g l(-1) yeast extract, 21.9 g l(-1) Pharmamedia, and an initial pH of 9.8. The optimized medium resulted in about a 20-fold increase in the enzyme activity as compared to that obtained in the basal medium.