In this study, work ethic was examined as a predictor of academic performance, compared with standardized test scores and high school grade point average (GPA). Academic performance was expanded to include student organizational citizenship behavior (OCB) and student counterproductive behavior, comprised of cheating and disengagement, in addition to college GPA. Results indicated that work ethic explained incremental variance in student OCB, cheating and disengagement beyond standardized test scores or high school GPA. However, work ethic did not explain incremental variance in college GPA. Specific work ethic dimensions were related to each outcome. These findings provide support for the importance of non-cognitive variables in academic contexts, particularly when considering an expanded performance domain. In addition, results provide additional validity evidence for the nature of work ethic as a multidimensional construct. (Contains 2 tables.)