The aim of this study was to find out the effect of selected factors on somatic cell count in the sheep milk during lactation. Monitoring took place in the 3 dairy sheep farms (East Friesian sheep, crossbreed Sumavska sheep and Lacaune). 20 ewes from each farm were included in the experiment. Milk yield was measured on the farms at regular monthly intervals during two lactation periods. The selected parameters (total bacteria count – TBC, somatic cells count – SCC) were determined in the individual samples of milk. The values were statistically evaluated by using analysis of covariance in Statistica. The results of this experiment have shown that SCC in sheep milk is directly dependent on the breed, stage of lactation, age of ewe, number of reared lambs, but also on the ways of milking and frequency of milking and the level of farm management.