Glucose and dextrin were compared for their ability to support toxinogenesis in cultures of strain D7 ofClostridium perfringenstype D with pH controlled at 7.0 or uncontrolled. At pH 7.0 both carbohydrates supported toxinogenesis equally: the yields of alpha, epsilon, kappa, and theta toxins were 20 MLD, 70,000 to 80,000 MLD, 400 to 500 arbitrary units (K.U.) and 30 hemolytic units (H.U.) respectively. With uncontrolled pH, dextrin was superior to glucose: with dextrin in the medium the yields were 10 MLD, 16,000 MLD, 200 K.U., and 3 H.U. while with glucose they were 1 MLD, 1500 MLD, 100 K.U., and 3 H.U. of alpha, epsilon, kappa, and theta toxins respectively.The time of epsilon toxin synthesis during fermentation at pH 7.0 was affected by the carbohydrate used. With dextrin, toxinogenesis paralleled growth, but with glucose most of the toxin was produced at the end of the growth period.Synthesis of epsilon, kappa, and theta toxins by three other strains ofC.perfringenstype D in cultures without pH control was also reduced consistently when dextrin was replaced with glucose. At pH 7.0 toxinogenesis was, with few exceptions, the same in cultures with dextrin and glucose.