This article describes the development of the Counseling Self-Estimate Inventory through 5 studies. A factor analysis (N = 213) yielded 5 factors that reflect counselor trainees' confidences in using microskills, attending to process, dealing with difficult client behaviors, behaving in a culturally competent way, and being aware of one's values. Reliability estimates indicate that the items are internally consistent (alpha = .93) and stable over time. Initial validity estimates show that the instrument is (a) positively related to counselor performance, self-concept, problem-solving appraisal, performance expectations, and class satisfaction; (b) negatively related to state and trait anxiety; (c) minimally related to aptitude, achievement, personality type, and defensiveness; and (d) sensitive to change over the course of master's practicum and across different levels of counselors. Also, trait anxiety and counseling self-efficacy were significant predictors of counselor trainee performance. The development of a reliable and valid counseling self-efficacy instrument has training and research implications.