The aim of this work is to determine the effect of the use of powder disinfectant on health of calves. On one farm, health was monitored in 80 Holstein calves housed under a shelter with continuous operation. A control group of 40 calves was housed in pens, which were only mechanically cleaned before housing. While the experimental group of another 40 calves were housed in pens which, in accordance with the producer´s recommendations, were treated with powder disinfectant (mixture of copper and iron salts, phosphates and inorganically bound chlorine) in addition to mechanical cleaning after drying. The use of a powder disinfectant during calf rearing led to a significant reduction (p < 0.05) in the incidence of diarrhoea (by -25%). In contrast, the use of disinfectant on the incidence of calf respiratory diseases has not been proved. The incidence of diarrhoea began in calves housed in disinfected pens by +6.4 days later (p < 0.001) in compared with calves housed in non-disinfected pens. Calves reared in pens treated with powder disinfectant also showed non-significantly shorter duration of diarrhoea (by -1.1 days) and significantly (p < 0.001) shorter duration of respiratory diseases (by -2.1 days).