The aim of this study was to establish physiological responses of Piemontese cows to different environmental conditions (ambient temperature, relative humidity and temperature-humidity index). To this end, 43 clinically healthy Piemontese cows aged 2-12 years were used to evaluate the effect of environmental conditions on haematological parameters. For each period, ambient temperature and relative humidity were recorded by means of a data logger and the temperature-humidity index (THI) was calculated as indicator of thermal comfort for cattle. Blood samples were collected at 4 time points under different environmental conditions (T1, T2, T3 and T4) and analysed for haematological parameters. One way repeated measure analysis of variance showed a statistically significant effect of time (P<0.0001) on RBC, Hb, Hct, MCV, MCH, MCHC, Plt, WBC, neutrophils, lymphocytes, monocytes and eosinophils. The majority of haematological values obtained in the present study, even though within the physiological range for cattle, showed that variations in haematological parameters are related to changes in ambient temperature, relative humidity and temperature-humidity index. These results provide insight into the physiological responses of Piemontese cows to different environmental conditions, allowing to better evaluate its ability to adapt and cope with environmental stress.