On a large pig farm with a known history of necrotic enteritis 12 pregnant gilts were vaccinated s. c. 7 and 2 weeks before expected farrowing with a commercial bacterin-toxoid preparation of toxigenic strains C. perfringens type C and D (DizevakR-Pliva, Zagreb). At the farrowing the titers of beta-antitoxins in serum samples from vaccinated gilts ranged from 9.0 to 26.0 IU/ml with a mean value of 14.16 IU/ml. Colostral titers varied from 12.0 IU/ml with a mean of 16.12 IU/ml. On the second day of life the mean serum titers between litters differed greatly from 4.75 to 24.0 IU/ml. By the age of 7 days the average serum titers were commonly lower and varied between the litters from 2.25 to 15.0 IU/ml, with a low of 1.5 to a high of 16.0 IU/ml in single animals. Ten (8.47%) out of a total of 118 piglets from vaccinated gilts died during the first 7 days of life but the losses were not caused by C. perfringens infection. In unvaccinated control animals 18 (15.9%) of 113 piglets died, eleven of them with clinical and pathoanatomical signs of necrotic enteritis. The affected piglets predominantly succumbed in the first 4 days of life. These data indicate that the investigated bacterin-toxoid can be successfully used in immunoprophylaxis of necrotic enteritis in piglets.