One of the main problems in rearing young cattle at livestock enterprises are invasive diseases, in particular, parasitic protozoa. It leads to a decrease in the protective functions of the animal's body and the loss of live weight gain and death of calves. The aim of the research was to study the economic damage from calves eimeriosis in the Uvinsky district of the Udmurt Republic. To carry out the experiment, according to the principle of analogue groups, 2 groups of calves aged 3-6 months were formed. Calves of the control group were without signs of intestinal coccidiosis invasion. Calves of the the experimental group were infected with Eimeriosis with different intensity of invasion. To determine the extent of invasion, coprological flotation methods of Fülleborn and Darling were used. During the study period, the weight gain of calves in the control group was 882.0 kg, in the experimental group - 675.0 kg. When calculating the economic damage, we took into account the death and decrease in the productivity of animals due to intestinal coccidiosis. The damage from eimeriosis of calves 3-6 months of age for 3 months of research on the farm amounted to 9746 rubles per animal. Large economic losses are made up of a decrease in the productive performance of the herd, an increase in feed conversion and mortality. One of the most important measures to break the epizootic chain of eimeriosis invasion in cattle is the development of timely control measures, the use of which can significantly increase the profitability of agricultural enterprises.