Infections in the neck layers and spaces are potentially life-threatening diseases causing further complications, like mediastinitis, airway obstruction, or sepsis. Despite of the need for a conservative approach, they still regularly require surgical intervention. Records of 17 patients with severe neck infections that were treated by wide external incision and open wound management were retrospectively analyzed. The aim of the study was to clinically characterize these most serious neck infections. The most common presenting symptoms were neck pain and tense neck mass (94-94%) regularly with fever (65%), always accompanied by a marked elevation of C reactive protein level (average 192 uG/l). These findings were constant and very similar among both the deep neck infection and necrotizing fasciitis cases. More than half of the patients (53%) had at least one systemic co-morbidity. The parapharyngeal space was most commonly affected (83%), but extended disease involving more than two major neck regions was found in 13 cases (76%). Dental (29%) was the most common primary infection, followed by peritonsillar abscess (23%), Microbiological results showed a wide variety of corresponding bacteria. Mediastinitis was developed in three cases (18%), and airway obstruction requiring tracheostomy in two cases (12%). All the patients survived. Severe neck infections are a heterogenous group of diseases regarding to the primary site of infection, microbiology, localisation and host reaction. However, rapidly developed, painful, tense neck mass with a highly elevated CRP level should always alert for an extended or phlegmonous process in the layers or spaces of the neck.