Introduction: Halo vest external stabilization is an alternative treatment to operative stabilization most unstable fractures of the upper cervical spine. The purpose of this paper is to familiarize readers with a method and to analyze its basic usefulness parameters – fusion rate and complications. Materials and methods: Retrospective analysis of medical documentation of 49 patients treated with external stabilization in years 2003-2010. We analyzed type of fracture, complication and fusion rate. Results: Radiological overall fusion rate was 86% after 12 weeks of treatment. In three cases external stabilization was maintained until achievement of the fusion evidence on radiograms (108, 129, 156 days). In three cases fusion was not achieved. Complication occurred in 22 cases (44%), but in 14 cases they were fully reversible, benign and have no long-term sequel. There is consensus that a very high, 95% fusion rate in patients with type III dens fractures, but halo vest efficiency in type II dens fractures are a matter of discussion. In our material, after 12 weeks of treatment we achieved 65% fusion rate, and 79% success including delayed fusion.