The purpose of this validity study was to improve measurement of coaching efficacy, an important variable in models of coaching effectiveness. A revised version of the coaching efficacy scale (CES) was developed for head coaches of high school teams (CES II-HST). Data were collected from head coaches of 14 relevant high school sports (N = 799). Exploratory factor analysis (n = 250) and a conceptual understanding of the construct of interest led to the selection of 18 items. A single-group confirmatory factor analysis (CFA; n = 549) provided evidence for close model-data fit. A multigroup CFA provided evidence for factorial invariance by gender of the coach (n = 588).