The aim of this study is to develop a valid and reliable scale named "Smartphone Self-Efficacy Scale". The purpose of the scale is to determine the smartphone self-efficacy levels of people. The study was carried out with 520 pre-service teachers in the spring academic term, and 103 pre-service teachers in the academic year of 2018-2019 autumn academic term. The pre-service teachers all were attending the Education Faculty of Mugla Sitki Kocman University. In order to determine the validity and reliability of the scale, exploratory and confirmatory factor analyses were conducted. As a result of the exploratory factor analysis, it was found that the scale is included one factor and 20 items. The Cronbach Alpha internal consistency coefficient of the scale was calculated as 0.97. Confirmatory factor analysis also showed that the goodness of fit indices was at an acceptable level. Therefore, according to the results of the both validity and reliability analyses "Smartphone Self-Efficacy Scale" is reliable.