PFAPA is a chronic condition, typically starting after 2 years old, in which fever occurs periodically (lasts for 3-7 days), accompanied by aphthous-like ulcers, pharyngitis and/or cervical adenitis (cervical lymfadenopathy).The patients have no clinical symptoms between episodes and it is required to exclude all other diseases (a Streptococcus infection) before confirming the diagnosis. The dramatic response to the treatment helps diagnosing PFAPA. We are presenting the case of a 17-monthold male patient, with the personal history of recurrent episodes of fever (onset at the age of one), who constantly received antibiotherapy. On the first examination of the patient in our service (at the age of 17 months) he presented hyperpyrexia and dysphonia; physical examination showed pharyngeal tonsils congested with hyperemia, white patches on the bilateral tonsils. Laboratory investigations performed at that time revealed leukocytosis with lymphomonocytosis. Suspicion was raised on infectious mononucleosis, but it was without serological confirmation. The child received only antipyretic treatment with favourable outcome (the patient had no fever after three days of evolution). Subsequently, the patient presented other 5 episodes of fever which disappeared after one dose of steroids. After 4-5 hours the fever disappeared. Physical examination showed pharyngeal congestion, the throat swab being constantly negative. The particularity of the case lies on the onset of the syndrome PFAPA onto a very small patient.