Training preservice teachers to develop a predisposition toward constructivist instruction is a major goal for many faculty in teacher education. One critical attribute of a constructivist teacher is a strong hold on pedagogical content knowledge. This study examined the prior knowledge of preservice science teachers and how that knowledge aligned with INTASC Standard I and the NSTA Core Knowledge Standards for science teachers. Basic content knowledge of twenty-four preservice teachers in an introductory science education course was assessed through released items from the grade 8 Trends in International Mathematics and Science Study (TIMSS) and the National Assessment of Educational Progress (NAEP) tests. Kruskal-Wallis analysis showed no significant differences in content knowledge across 3 content domains.