We provide an overview of opportunistic fungal infections caused by Acremonium (Cephalosporium) species and discuss the classification of these species as well as the diagnosis and treatment of acremonium infections. We used a microdilution broth method to compare in vitro susceptibilities and minimum inhibitory concentrations and minimum fungicidal concentrations of amphotericin B, miconazole, itraconazole, 5-fluorocytosine, fluconazole, and ketoconazole for 33 clinical and environmental isolates of Acremonium. In general, the isolates tested displayed little susceptibility to the antifungals tested. Fluconazole and 5-fluorocytosine were ineffective in all cases. The efficacy of the remaining drugs was dependent on the strain. Amphotericin B showed the best results.