Infectious mononucleosis (IM) is a relatively common infection in healthy young patients with few complications. Here we present a case of severe IM complicated with extensive bilateral peritonsillar abscesses. Clinicians should be aware of this complication of IM in patients with persistent or progressive symptoms. Epstein-Barr virus is a herpes virus that causes infectious mononucleosis (IM) in young adults. Symptoms are usually sore throat, lymphadenopathy, fever, and malaise Sylvester et al. [1]. IM has been associated with complications such as hemolytic anemia, myocarditis, splenic rupture, thrombocytopenia, hepatitis, etc Sylvester et al. [1]. There have been reports of suppurative processes involving the tonsils such as intratonsillar or peritonsillar abscesses, but these seem to be rare complications. Herein, we present a case of bilateral peritonsillar abscesses in a patient with severe mononucleosis.