The aim of this experiment was to estimate possible associations between GHRL G375A genotypes and some milk performance traits (yields of milk, protein and fat, and protein and fat content). The study included Polish Holstein–Friesian strain Red-and-White cows. The ACRS and PCR-RFLP method was used to identification genotypes. GHRL G375A frequencies were as follow: AA – 0.86, AG- 0.14, and GG – was not found, while allele frequencies were: A – 0.93 and G – 0.07. In this study, no statistically significant correlation between GHRL genotypes and analyzed traits was found, however, a tendency to maintain a relationship of genotypes with milk production traits is shown.