Overconfidence in clinical judgment is a common problem among counselors that undermines the validity of the counselors' assessments and, by implication, the quality of client services. The authors evaluated an instructional module designed to reduce overconfidence among counselor trainees who completed an assessment task that exposed them to some of the complexities and pitfalls of clinical judgment. Although all counselor trainees were generally overconfident at both pretest and posttest, the module led to reductions in overconfidence only for the trainees who were exposed to it. It is suggested that counseling programs need to teach trainees to reflect critically on their inferential processes to improve the quality of their assessments.