Standardized test data indicate that student achievement in science is a problem both nationally and locally. At the study site, only a small percentage of fifth-grade students score at the advanced level on the Maryland state science assessment (MSA). In addition, the performance of African American, economically disadvantaged, and special education students is well below that of the general student population. Some studies have shown that teacher self-efficacy affects student achievement. Therefore, the purpose of this study was to explore the relationship between fifth-grade teacher inquiry science instruction self-efficacy scores and the scores of their students on the MSA. Bandura\u27s work on the effect of self-efficacy on human behavior provided the theoretical basis for this study. The research questions examined the relationship between teacher inquiry science instructional self-efficacy scores and students\u27 science MSA scores as well as the relationship by student subgroups. A correlational research design was used. The Teaching Science as Inquiry survey instrument was used to quantify teacher self-efficacy, and archival MSA data were the source for student scores. The study included data from 22 teachers and 1,625 of their students. A 2-tailed Pearson coefficient analysis revealed significant, positive relationships with regard to overall student achievement (r20 = .724, p \u3c .01) and the achievement of each of the subgroups (African American: r20 = .549, p \u3c .01; economically disadvantaged: r20 = .655, p \u3c .01; and special education: r18 = .532, p \u3c .05). The results of this study present an opportunity for positive social change because the local school system can provide professional development that may increase teacher inquiry science instruction self-efficacy as a possible means to improve overall science achievement and to reduce achievement gaps
