Peritonsillar abscess remains the most common deep infection of the head and neck. The condition occurs primarily in young adults, most often during November to December and April to May, coinciding with the highest incidence of streptococcal pharyngitis and exudative tonsillitis. A peritonsillar abscess is a polymicrobial infection, but Group A streptococcus is the predominate organism. Symptoms generally include fever, malaise, sore throat, dysphagia, and otalgia. Physical findings may include trismus and a muffled voice (also called "hot potato voice"). Drainage of the abscess, antibiotics, and supportive therapy for maintaining hydration and pain control are the foundation of treatment. Antibiotics effective against Group A streptococcus and oral anaerobes should be first-line therapy. Steroids may be helpful in reducing symptoms and speeding recovery. To avoid potential serious complications, prompt recognition and initiation of therapy is important. Family physicians with appropriate training and experience can diagnose and treat most patients with peritonsillar abscess. (Am Fam Physician.