We estimated the genetic parameters of citric acid content in milk of Holstein primiparous cows in first test-day, up to 40 days in milk. Its content was the highest after calving and decreased as the lactation progressed. Citrate content was significantly affected also by the age of cow at first calving (higher in older cows) and by the season (higher in January–June compare to July–December). The heritability estimate was h2 = 0.26. We found positive phenotypic and genetic correlations between citrate and acetone (rGxGy = 0.40; rPxPy = 0.45) and β-hydroxybutyrate (rGxGy = 0.09; rPxPy = 0.17). Higher content of citrate was accompanied with higher fat content (rPxPy=0.23), and with higher fat to protein (rPxPy = 0.31) and fat to lactose (rPxPy = 0.23) ratios. The association with fat content was not confirmed on the genetic level (rGxGy = -0.07) indicating different genetic predisposition of both traits. Negative phenotypic and genetic correlations were estimated between citrate and protein content (rPxPy = -0.20; rGxGy = -0.18) and between citrate and body condition score (rPxPy = -0.10; rGxGy = -0.17). Our results confirmed that citrate is a good biomarker of energy balance, and its employment could be beneficial for the genetic evaluation and selection of dairy cattle for resistance to ketosis.