Abstract. Weaning performance of 7 032 purebred Hungarian Fleckvieh calves (3 650 male and 3 382 female) born between 1981 and 2003 from 1 452 cows mated with 113 sires were analysed in two farms. The aim of the study was to evaluate the effect of environmental factors on weaning traits. Farm, age of cows, year of birth, season of birth and sex of calves as fixed, while sire as a random effect was treated. Data were analysed with HARVEY’s (1990) Least Square Maximum Likelihood Computer Program. The overall mean value and standard error of weaning weight, preweaning daily gain and 205-day weight were 214 ± 3.01 kg, 980 ± 17.31 g/day and 236 ± 3.40 kg, respectively. The mean age of the analysed calves was 181 ± 33 days. The results of the examination show that weaning weight, preweaning daily gain and 205-day weight increased as far as the 6 year age cows (the maximum were 226 ± 3.13 kg, 1 049 ± 17.89 g/day, 251 ± 3.54 kg). As for the season effect the calves born in summer were smaller (208 ± 3.12 kg, 946 ± 17.84 g/day and 230 ± 3.52 kg) than that of born in the other seasons (P<0.001). The male calves were heavier than females, the difference was 12 kg, 50 g/day, 16 kg, respectively (P<0.001). The best year was 1985, the worst 2000.