In the pre-antibiotic era, parapharyngeal infection was a frequent complication of tonsillitis. However, due to widespread use of antibiotics, its frequency has decreased and consequently the infection is quite uncommon nowadays. Knowledge of neck anatomy, especially of the cervical fascia, is essential for a better understanding of pathogenesis and route of spread of infections in the parapharyngeal space. The cervical fascia spreads throughout the neck tissue, divides it and forms the interfascial neck spaces. These spaces communicate with each other, which brings a risk of uncontrolled pathogen expansion. The clinical manifestation of this infection consists of fever, trismus, odynophagia, intense local pain and swelling of the lateral pharyngeal wall with propagation into the hypopharynx. The progression of the infection may lead to complications, even fatal. This case report presents a 42-year old male with a peritonsillar abscess expanding into the parapharyngeal space. The infection has spread from its initial site distally into the visceral space, causing further complications. The use of the appropriate therapy resolved the pathological process, therefore allowing the patient’s full recovery.