The purpose of this study was to clarify the construct of academic competence and develop a valid teacher rating instrument to assess this construct. A 95-item pilot scale, the Academic Competence Evaluation Scales (ACES), was developed to assess the theoretical components (i.e., academic skills, study skills, academic motivation, interpersonal skills, and academic self-concept) hypothesized to contribute to the construct of academic competence. The AGES was administered to 56 teachers who rated 300 students in Grades 1 through 6. To explore convergent and discriminant validity, 13 teachers completed ratings of social skills, problem behaviors, and academic competence las measured by the Social Skills Rating System; SSRS) for 60 students. In addition, 32 students completed the Iowa Test of Basic Skills (ITBS), a popular measure of academic achievement. Teacher feedback, item Importance ratings, item-ITBS correlations, and the results of an exploratory factor analysis were used to eliminate 35 items from the pilot scale. The resulting 60-item version of the AGES consists of five related scales: Academic Skills, Interpersonal Skills, Academic Motivation, Participation, and Study Skills. Internal consistency (median alpha = .95) and test-retest stability (median r = .83) were high for the AGES, and correlational analyses indicated that scores from the AGES are valid indicators of student academic competence. Implications for using the AGES are discussed, and suggestions are offered for research necessary to advance the development of the AGES as a reliable and valid clinical tool.