Prevalence of failure of passive transfer (FPT) of immunity remains relatively high worldwide. The aim of this study was to estimate the FPT prevalence in Czech dairy calves and to evaluate the selected factors – breed, herd size, sex of calves, single versus twin births and the influence of the season of birth. A total of 1,175 serum samples were taken from calves of Czech Fleckvieh and Holstein breed from 33 herds between October 2015 and October 2017. Serum IgG concentration was determined by reference method for IgG determination – radial immunodiffusion. Statistical evaluation was performed by Kruskal‑Wallis test. The concentration of IgG ranged from 1.5 to 46.6 g / L with average value 13.7 g / L and was significantly influenced by breed, size of the herd and season. Using the criterion IgG < 10 g / L, it was found that 34.6 % of calves had FPT. The prevalence of FPT by breed was 42.9 % vs. 24.2 % (Czech Fleckvieh vs. Holstein), by size of the herd 45.0, 44.4, 25.5 and 22.0 % (< 200, 200 – 399, 400 – 599 and ≥ 600 cows per herd, respectively) and by season 25.3, 34.6, 29.9 and 52.5 % (spring, summer, autumn and winter, respectively). The sex of calves was not found to be a statistically significant factor. The study in newborn calves showed that FPT is still an important problem in Czech dairy herds, especially in the Czech Fleckvieh breed. In smaller herds and especially in the winter, the prevalence of FPT was very high.