Productive and reproductive performance are some of the most important parameters in dairy cattle because they affect profitability of these systems. Marker-assisted selection is a useful tool to improve efficiency of dairy herds, because it allows identification of genetic differences related to a higher productive potential. Inhibin protein belongs to the transforming growth factor β super family, and its function is to modulate the secretion and action of the FSH. The goal of this research was to determine the effect of A192G polymorphism on productive and reproductive traits in Antioquia Holstein cows. The PCR-RFLP technique was used to amplify a segment of 249bp of the bovine inhibin α gene (INHA), and then digested with the enzyme MspI. It was analyzed 1240 lactations from 356 dairy cows. The effect of the INHA genotypes on the traits was determinate by a mixed linear model and Tukey test was used to establish significant differences between means for the 3 genotypes. The effect of allelic substitution was made through a linear regression model where the genotypes AA, AG and GG were transformed into a quantitative scale of 0, 1 and 2, according to the number of G alleles. In Antioquia Holstein cattle the most common genotype was AG (0.529), followed by AA (0.269) and GG (0.201). Allele frequencies were 0.534 for A and 0.466 for G. The INHA genotypes did not exerted a significant effect on the principal productive parameters, except for fat percentage, where GG animals presented the highest value for this trait. Despite it was not a significant effect of this polymorphism on reproductive parameters, Tukey test showed that G allele tended to have a detrimental effect on female fertility, increasing the calving interval and the number of services per conception, decreasing the reproductive efficiency of the herds. Further studies are required to determine whether this SNP may be used as a molecular marker.