The study was carried out to determine the knowledge of child development students about foreign body aspiration in children, their first aid self-efficacy for foreign body aspiration, and to examine the relationship between their knowledge levels and first aid self-efficacy. The study was of descriptive and cross-sectional type. 118 students were included in the study. Descriptive Characteristics Form, Knowledge Evaluation Form about Foreign Body Aspiration in Children, and First Aid Self-Efficacy in Children with Foreign Body Aspiration Form were used to collect the study data. Foreign body aspiration knowledge scores of students were determined as 10.94 ± 2.29. The first aid self-efficacy score of students was low. A positive and significant relationship was found between students' knowledge scores and self-efficacy scores (p < 0.05). Although the level of knowledge of students about foreign body aspiration in children is above average, their first aid self-efficacy was found to be low.