Introduction Descending necrotizing mediastinitis is usually a polymicrobial process and can lead to a serious clinical condition. It can be caused by formation of an oropharyngeal or odontogenic abscess that spreads the infection to the neck tissues and further via the cervical fascia planes to the mediastinum. Clinically there are two forms of cervical necrotizing fasciitis (CNF): suppurative and gaseous which if diagnosed late can have lethal effects. Multidisciplinary treatment is often essential for the recovery. Material and methods We would like to present our experience in managing a young adult patient who suffered from descending necrotizing mediastinitis (DNM) of odontogenic origin and describe controversies associated with its treatment. Incision and drainage of the neck were performed in the patient, antibiotic therapy was given, and oral cavity was irrigated, as well as parenteral and enteral immunonutrition enriched with omega-3 fatty acids (Omegaven) and glutamine (Dipeptiven) were started. Moreover, dental treatment was carried out, after which the patient’s clinical status improved. Results Dental treatment influenced the postoperative course. Multidisciplinary approach led to a full recovery of the patient. Conclusions Early multidisciplinary aggressive treatment of oropharyngeal infection and cervical necrotizing fasciitis is a life-saving procedure. Thorough surveillance with repeated CT scans, white blood cells and C-reactive protein evaluation, monitoring of bacteriological culture and surgical procedures which are performed in descending necrotizing mediastinitis facilitate the treatment and allow to avoid complications