The paper presents estimates of the effective population size of Large White pigs, obtained by three different methods based on the use of five loci microsatellite DNA polymorphism. It is found that the Slatkin’s method is most conservative. Calculated by this method effective size of the population studied pigs were 33.3 individuals (with lower and upper bounds of 12.9 and 372.2 individuals, respectively). Hill’s method gives a more specific assessment as directly effective population size and its confidence interval. In general, research shows that the effective size of the studied population of Large White pigs is in the range of 50-100 individuals (with a confidence interval – from 10 to 300 individuals). Our estimates of effective population size of Large White pigs in Ukraine are very close to those obtained by other researchers for the common European pig breeds.