This study was aimed at determining the adaptation levels of pregnant Brown Swiss and Simmental cows, imported from Austria to a dairy cattle enterprise in Manisa, according to their first year performances. Reproduction and milk yield performances of Brown Swiss and Simmental cows was focused in this paper. Insemination, pregnancy and birth parameters for Brown Swiss and Simmental cows were found to be similar. The first insemination interval and gestation length of Simmental cows were shorter than Brown Swiss cows. For Brown Swiss and Simmental cows, real milk yield was 9205.61 L and 8351.05 L; milk yield for 305- days was 8115.71 L and 7693.44 L; the lactation period was 356.0 days and 337.7 days respectively. The differences between breeds according to real and 305-days milk yield were statistically significant. The cows that calved in November and December reached a higher milk yield performance. The effect of calving month on cows’ persistence in first lactation was significant, but the effect of breeds was not significant. Considering that the mean milk yields of Brown Swiss and Simmental cows in first lactation were over eight thousand liters, it can be said that the cows imported from Austria genetically have dairy potential and they can show this dairy potential from the first yield-year onwards.