Background: Vitamins A, C and E are important parts of the antioxidant barrier. Polish data on antioxidant vitamins deficiency in the population are rare, especially among physically active people with metabolic disorders. The aim of this study was to evaluate the serum concentrations of vitamins A, C and E in people with metabolic syndrome (MS) working in agriculture, the prevalence of their deficiency in these workers, and the correlation between antioxidant vitamins concentration and traditional biomarkers of cardiovascular diseases. Material and Methods: The study included 332 residents of the Łódź Voivodeship working in agriculture: 231 people with MS and 101 healthy ones. The serum concentrations of vitamins A, C and E were assessed using the chemiluminescent immunoassay technology. The antioxidant vitamins intake was assessed by means of a 24-h recall questionnaire using Diet 5.0 software. Results: The mean serum concentrations of vitamins A, C and E were significantly lower in the MS workers than in the healthy ones No correlation was found between the antioxidant vitamins concentration and the dietary intake but there was a correlation between the antioxidant vitamins concentration and high-density lipoprotein cholesterol (HDL-C). A correlation was found between the serum concentrations of vitamins A and C, and vitamins A and E, in the MS workers. Conclusions: The serum concentrations of antioxidant vitamins in the MS workers were significantly lower than in the healthy controls, despite the similar physical activity level. The dietary intake had no impact on the serum concentrations of these vitamins. The HDL-C concentration in the MS workers correlated with the concentrations of all antioxidant vitamins. Med Pr. 2021;72(2):123–9