Suppurative thyroiditis is rare, and the major pathogens are Staphylococcus and Streptococcus species. We present a case caused by Acinetobacter baumanii, which has never before been reported. We review another 191 cases from the English-language literature (1980 to April 1997) and make a comparison with a review of 224 cases (1900-1980). As the numbers of immunocompromised patients increase, cases of suppurative thyroiditis are increasing. Pneumocystis carinii has become an important pathogen. Most patients (83.1%) with bacterial infections were euthyroid, whereas those with fungal or mycobacterial infections tended to be hypothyroid (62.5%) and hyperthyroid (50%), respectively.