The article presents the results of analysis of 482 forensic biological and forensic cytological expertises on cases of sexual crimes. A presence of different types of such crimes has been noted. Expertises’ effectiveness when examining content of vagina, oral cavity and rectum, impression smears and lavages from suspects’ genital organs, subungual content of victims and suspects and other objects has been determined. The dependence of expertises’ effectiveness on the terms of object removal has been noted. The article presents a number of objects’ examination methods (luminescent-microscopic spermatozoids’ identification, diagnosis of cells origin from mucous membranes of the vagina and oral cavity, determination of group belonging of specific cells in specimens, diagnosis of fecal masses presence) allowing to improve expertises’ quality.