In the Southwestern Atlantic coast, two species of the bottlenose dolphin Tursiops truncatus gephyreus and T. truncatus cf. truncatus were observed, distributed north and south of Santa Catarina State. In this study, the niche overlap of these two subspecies was investigated using existing spatial data. Monte Carlo techniques were used to test the observed overlapping index against randomness. Results indicated there was low niche overlapping and it was not random.