This study aimed at confirming the consumption of leafcutter ants by Myrmecophaga tridactyla at a Pinus plantation in Parana State, Brazil. The evaluation was developed in a study area of 8,000 ha in 2007 and 2008. Analysis of fecal and stomach samples confirmed the consumption of leafcutter ants of the genera Acromyrmex and Atta. In addition, other ant genera were identified, such as Camponotus, Solenopsis, Pheidole, Forelius (cf.), Ectatomma, Odontomachus and Labidus, and the termite genera Nasutitermes, Syntermes and Neocapritermes. These results contribute to the knowledge of the diet of giant anteaters, especially in southern Brazil.