The objective of the present study was to search for the methods for the enhancement of the effectiveness of forensic medical examination of material evidence during the investigations into the crimes against sexual immunity and personal sexual freedom. The work included the analysis of the relevant expert conclusions and copies of the decisions approving the performance of the forensic medical expertises. The study was carried out with the use of the following methods: the extraction of necessary data from the primary materials, their systematization and treatment by the methods of descriptive and analytical statistics. The study has demonstrated significant differences in the frequency of discovery of biological evidence of sexual offence depending on the character of the objects available for the examination and the time of their obtaining; these parameters were shown to depend on a variety of factors. It is concluded that the multidisciplinary approach to the selection and examination of material evidence for the purpose of the investigation into the cases of sexual offence makes it possible to considerably enhance the effectiveness of forensic medical expertises for the search of biological evidence of sexual crimes and thereby to improve the quality of this work.