Haemogregarines were recorded in caimans Caiman crocodilus yacare from Pantanal. This study was carried out in seasonal ponds at the Miranda- Abobral subregion of Pantanal, State of Mato Grosso do Sul, western Brazil, from 1998 to 1999. Smears from 28 caimans were examined and 20 (71.4%) presented infection by a haemogregarine. Infections were observed in 11 males and 9 females. Morphological and morphometric observations suggest that the parasite forms found in this work are Hepatozoon caimani.