PURPOSE: To investigate the knowledge, perceptions and practices of preschool teachers regarding children with hearing alterations. METHODS: A descriptive cross-sectional study was carried out through structured interviews with 45 preschool teachers from the public education system of Belo Horizonte (MG, Brazil). Interviews were recorded, transcribed and later analyzed. RESULTS: The majority of the subjects showed little knowledge, at times vague and of common-sense, regarding hearing loss. However, conscience of the necessity of learning more about the subject for a better professional performance is clear. Despite the lack of information, teachers demonstrated knowing some characteristics of children with hearing loss, and explicit conducts to be carried out in the classroom. Almost all subjects claimed not to know the school hearing screening. CONCLUSION: The knowledge, practices and perceptions displayed by the subjects revealed wide variation of concepts, attitudes and strategies. However, much is based on common-sense or intuition, due to lack of experience and training of teachers to deal with children with hearing loss.