Embryonic loss occurring in the first week of the incubation is termed early embryonic mortality. Environmental, technological and genetic factors can be responsible forits appearance. The examination of genetic background of embryonic death is justified when the breeding and hatching technological parameters are optimal. Disposition of early embryonic mortality can be inherited and it can accumulate in a stock, which will finally deteriorate its fertility indices. Although the heritability value of reproductiveness is poor, h2=0.1−0.2, even so, during the selection still should be considered. This paper offers a short review on the special features of early embryonic development in poultry and examination methods forpossible genetic background of early embryonic abnormalities and mortality. The application of cytogenetical and embryological methods may be of major relevance in the improvement of the reproduction traits of poultry species.