The most significant effects of milk protein genes on milk production parameters, coagulation properties and breeding values (BV) for milk production in Czech Fleckvieh cattle was proved in CSN3 gene with its main significant effect on milk quality and coagulation properties (protein content, casein content, curd quality and firmness, and coagulation time), and significant effect on BV for protein content and protein yield. The most favourable values of milk quality parameters were linked with genotypeBB compared to negative impact of genotypes containing allele E. LGB gene significantly affected whey protein content and casein content with positive impact of BB genotype. Significant effect of CSN2 gene was found on casein content and BV for production of milk, protein and fat. The most favourable genotypes were A1A2, A1A1, A2A2, and A1B. CSN1S1 gene was significantly linked with BV for milk yield. The highest value was found in genotype CC.