This study examined the relation between 9 and 12-year-old children’s interest in science and their scientific thinking skills. Eighty children aged 9 and 12 years and their parents reported their interest in science and children answered epistemological understanding questions and solved scientific reasoning problems during a one-time laboratory visit. In addition, children answered questions concerning their concept of science, their parents’ interest in science, and individual factors related to scientific thinking. During the child’s participation, their parent filled out demographic, academic achievement, and their own interest in science questionnaires. Findings reveal that children’s interest in science and concept of science related to their epistemological understanding, and the relation between children’s interest in science and epistemological understanding is mediated by children’s critical thinking skills. Results further showed that children’s age and academic achievement, but not interest in science, related to their scientific reasoning skills. Other findings revealed that children’s identification with science as an interest was the predominant characteristic of interest to relate to epistemological understanding, and that children’s interest in science related to children’s perception of their mothers as interested in science. These findings are discussed in relation to their implications for further research and educational implementation.