Phlegmons of the neck originate from infectious diseases of head and neck. Odontogeneous inflammation of the oral cavity is most frquently primary lesion, followed by sinusitis, otitis, as well as radiation therapy and surgical procedures. Phlegmons of head and neck can drain into the spaces among the muscles, aponevrosis, organs inside the neck like sublingual space, lateral pharyngeal space, retro-pharyngeal space or pre-vertebral space. We hereby report our experience with 7 patients treated from 2001 to 2005.