Allowing for current state of biological and medical science, the forensic medical examination of male reproductive function should be subdivided into two groups: 1) examination of disputable paternity when there is a child (fetus) by using molecular-genetic methods; 2) other examinations without a child (fetus). In the latter case, when solving a question as to the sperm fertility, it is not enough to make the ejaculate examination by applying routine methods. So as to ensure objective appraisal of spermatogeneous function it is expedient to use the whole ensemble of the present-day methods, which allow for manifold physiological characteristics of the male reproductive system.