An eight-month-old apathic cat was referred to the Department of Medicine and Clinical Biology of SmallAnimals of the Ghent University Faculty of Veterinary Medicine, Merelbeke, Belgium. The cat had a severecase of non-regenerative anemia with a hematocrit of only 2.9%. Cytological examination of a bone marrowaspirate led to the diagnosis of pure red cell aplasia (PRCA). Additionally, a PCR assay for “Candidatus Mycoplasmahaemominutum” (“Candidatus M. haemominutum”) DNA was positive. Although unproven, an infectionwith “Candidatus M. haemominutum” could have contributed to the immune-mediated destruction ofred blood cell precursors. The cat recovered completely after treatment, which consisted of multiple bloodtransfusions, antimicrobial agents, and long-term prednisolone therapy (10 months). There were no signs ofclinical relapse at 20 months after cessation of therapy.