Mumps currently is a vaccine-preventable infections. However, mumps still remains an urgent problem all over the world, due to periodic increases in the incidence in older children (including the vaccinated ones against this infection), in adults (the disease often does not go smoothly with involving various organs in the pathological process and systems). The literature describes the various adverse effects of male mumps, including infertility, testicular atrophy, testicular tumors, impotence, gynecomastia, etc. The article provides information on the incidence of mumps in the Russian Federation and St. Petersburg, the clinical manifestation of the infection. It was noted that in adolescent boys and men, the presence of orchitis (orchoepididymitis) is a frequent symptom of the disease. It is shown in the article, that testicular inflammation rate increases with age of patients. A brief description of modern methods of laboratory diagnostics and therapy is given in accordance with clinical recommendations and treatment standards. A clinical case of mumps, combined severe form (mumps + orchoepididymitis), in a 17-year-old boy is presented in this article. The features of the course of the disease, the results of laboratory and instrumental examination and treatment have been analyzed in this item. Conservative therapy (antiviral and antibacterial) of mumps, as well as timely surgical treatment of orchoepididymitis, led to a complete clinical and laboratory recovery of the patient.