The measurement of teacher self-efficacy has a history of more than 30 years. The purpose of this research is to evaluate the development and validation of a scale to measure the science teaching self-efficacy of primary school teachers. Therefore, a scale has been created to measure primary school teachers’ science self-efficacy and the evidence for validity of the scale is presented in this study. Self-efficacy, as defined by Bandura, was the theoretical framework for the development of the scale. Data collection for this study occurred during 2014-2015 academic year. The scale applied to 135 science teachers in primary school. All of these participants completed the Self-Efficacy for Science Teaching Scale (SSTS) in January 2015 and again in June 2015. “The Self-Efficacy for Science Teaching Scale (SSTS)” was developed and has undergone revisions to the original version through processes defined in this study. The SSTS is comprised of three parts: “Science Teaching Self-Efficacy (STSE), Efficacy for Understanding Science Content (EUSC) and Efficacy for Teaching Science Content (ETSC)”. Reliability for each part of the SSTS was found to be acceptable for both versions of the scale. Evidence of validity and reliability were collected to determine if the SSTS is an adequate scale to measure the science teaching self-efficacy of primary school teachers. Findings indicate that reliability and validity of scale is adequate.