Mild to marked splenomegaly was observed in three of four rheas that died acutely in three unrelated commercial ratite facilities in Southeastern Louisiana. Mortalities occurred within a 5-week period in birds ranging from 2 months to 3 years of age. Multifocal hepatic and splenic necrosis with mononuclear cell infiltrates, typical of chlamydiosis in other avian species, was present on histopathologic sections. The diagnoses were confirmed by demonstration of inclusion bodies in splenic impression smears and fluorescent-antibody testing performed on Vero cell cultures.