Thyroid abcess and acute suppurative thyroiditis are uncommon, representing 0.1 to 0.7% of surgically treated thyroid pathologies. More common in children than in adults, this rarity is associated with poorly indicative clinical symptoms, thus making diagnosis difficult. Five cases reports are presented, 4 of them in adults, illustrating the diagnostic difficulties and the various etiopathological mechanism, thereby explaining the wide diversity of pathogenic agents responsible. Treatment includes surgery (drainage or (partial) thyroidectomy, depending upon the presence or not of an underlying thyroid pathology) and intravenous antibiotics. It is absolutely necessary to eliminate the source of the infection, often a piriform sinus fistula whose total resection effectively prevents a relapse (1 case in this series).