Objective:Our aim was to determine the degree of knowledge about endocarditis prophylaxis (EP) among dental students, paediatric dentistry residents and specialists in paediatric dentistry, and to identify required attention areas.Material and methods: A cross-sectional study with 155 participants divided into three study groups was given a questionnaire to evaluate the knowledge of endocarditis prophylaxis, consisting of three areas: dental procedures, dose/medication and heart condition. Data were analysed with analysis of variance (ANOVA), using generalized linear models.Results: We stratified EP knowledge in three areas: dental procedures (no differences), dose/medication (statistically significant difference between group 2 and 3 (84.62 % vs. 38.89%, p = 0.044) and heart condition (no differences but low (35.48%, 53.85%, and 44.44%). Conclusions: This study was able to identify the knowledge degree of inadequate dental procedures in groups, having a greater knowledge in dose/medications those in paediatric dentistry residents. The area that requires more attention and reinforcement of the three groups is the one on heart condition area. Therefore it’s necessary to reinforce the endocarditis prophylaxis knowledge in undergraduate and postgraduate programs; and encourage paediatric dentistry to keep up-to-date on this issue.