The paper discusses the situation in the endangered autochthonous Black Slavonian Breed, developed in Croatia. A program for preserving this breed was initiated in 1996, which allowed the size of effective population (Ne) to grow from 18.46 to 32.32. Production properties of the Black Slavonian Breed are presented, i.e. litter size and fattening properties. According to the obtained results, production properties of this breed are rather limited. The number of liveborn and reared pigs per litter is 6.89 and 5.76 respectively. Under extensive conditions of fattening, daily gain in body mass starting at 27.20 and reaching 106.05 kg was 478 g, meat percentage being 42.95%.