Body index measurements on 2248 horses registered by the Brazilian Association of Pantaneiro Horse Breeders (ABCCP), in the period from 1972 to 2000 were analyzed. Data was analyzed using SAS and DFREML to calculate genetic parameters. The Dactyl Thoracic Index indicated that these animals are intermediary (not light horses but not suitable for traction), while the BARON and CREVAT index confirmed this result. The Chest Index presented animals that are good for speed as they have long legs but looking at the Body index the indication was that these horses are neither suitable for speed nor traction (intermediary). The analysis of other conformation indices indicated that, in general, these horses are medilines, show good speed and chest development, making them suitable for dealing with cattle and resistance for long treks. The environmental factor analysis verified that these horses have changed in recent years possibly due to selection by the breeder which may affect their adaptive capacity.