OBJECTIVE: To present a clinical case of a retropharyngeal abscess in a teenager, and to review existing literature on the subject. CASE REPORT: Patient, female, 17 years old, student, a native of Oyster River, states that there began 20 days under the "cold" was then treated with symptomatic for 7 days without improvement, progressing to left cervical swelling associated pain, high fever and poor general condition, sought medical attention in your city, started amoxicillin-clavulanate, with improvement in fever. Evolving with neck immobility, poor general condition, anorexia, and referred to the Department of Otolaryngology, Sao Jose do Avai Hospital. The Computerized Tomography examination had no changes except a slight swelling in the left cervical region. Asked Ultrasonography of the neck and neck computed tomography, showing extensive retropharyngeal abscess extending to the mediastinum. Patient referred to the surgical center, being punctured in the left retropharyngeal space and drainage of retropharyngeal abscess with presence of abundant pus and antibiotics broad spectrum intravenous. Hospital high after three days, with good clinical CONCLUSION: retropharyngeal abscess is considered serious disease with serious respiratory commitment. Generally the results from infectious processes involving the upper aerodigestive tract. The delay in diagnosis can result in high morbidity and mortality, requiring immediate medical treatment and surgery.