The aim of the study was to find out the effect of different levels of ventilation of outdoor individual hutches on the performance and health of calves. The monitoring was carried out on one farm with Holstein calves during two years. The calves were housed in outdoor individual hutches with different orientation the entrance to the windward side and leeward and with different levels of ventilation. The temperature and relative humidity of the air and the wind speed, the temperature-humidity climate, the cooling value of breeding environment in 192 calf hutches, including the live weight and health status of the stabled calves were determined during the experiment. The obtained data were evaluated in the program TIBCO Statistics. Based on the results, it is possible to state that calves reared in hutches with the entrance located on the windward side and closed regulating air outlets achieved the lowest live weight at weaning and the lowest weight gain compared to other calves. This is because these calves were exposed to high cooling due to the higher air flow speed in the VIB and consequently had a higher incidence of diarrhoea and respiratory disease.