This preliminary study assessed the knowledge and practices of dentists in the prevention of infective endocarditis (IE). The study included 21 dentists working at two public hospitals in Brazil who cared for children with special needs who also have cardiac conditions. The data from a semistructured interview were processed for qualitative and quantitative analysis. All subjects defined IE correctly. Most subjects (81%) said they had treated patients with a previous history of IE and 7 (33%) stated that many guardians seemed to be afraid to mention that their child had a previous history of IE. The main risk of infectivity was the oral cavity according to 16 subjects (76%). Nine subjects (43%) considered a dental procedure involving any amount of bleeding as being a risk, and periodontal/endodontic treatments were mentioned by 5 (24%) as procedures that needed antibiotic prophylaxis. As for prophylactic treatment, only 7 subjects (33%) said they followed the American Heart Association guidelines. The authors concluded that the subjects' knowledge and practices in preventing IE were inadequate.