The aim of this study was to obtain information on the possible influence of the bovine growth hormone gene (bGH) on gametogenesis and reproductive parameters of a 2-year-old Polish Landrace transgenic boar. The bGH gene construct had been introduced into the zygote of the boar with the use of the microinjection technique. On the basis of the available documentation we established that the fertility of the investigated transgenic (bGH) boar was low in comparison with other animals of the Polish Landrace breed, with a poor libido, ineffective matings and, on average, 3 live piglets less per litter. Samples of testis tissue from the boar were obtained after castration. In total, we observed 100 spermatocytes and all of them had normally paired bivalents. It is possible that the boar?s lower fertility was caused by some, as yet unknown factor.