Teacher self-efficacy, the belief teachers have that they can make a difference for their students or have a positive impact on their students' academic careers, has been studied for years. Very little is known about teacher self-efficacy in school librarians, however. The following study examined the difference in school librarians' teacher self-efficacy among those who worked in elementary, middle, and high schools. The study also attempted to determine if elementary school librarians' self-efficacy could be a predictor of reading scores for the schools' overall average rates on the Virginia Standards of Learning assessment. This quantitative study addressed the gaps in the literature by indicating that there is no difference in the levels of teacher self-efficacy among elementary, middle, and high school librarians, and found a weak but positive predictive relationship between the self-efficacy levels and the schools' overall average pass rates on standardized testing. The researchers noted the need for an instrument designed strictly for measuring the self-efficacy of school librarians, based on the myriad tasks they perform beyond the teaching role.