This study reports the development and initial validation of the Career Counseling Outcome Questionnaire (CCOQ) in two individual career counseling settings using a college sample ( n = 1,140) and a community sample ( n = 161). Exploratory and confirmatory factor analyses revealed five correlated factors in both samples: (a) knowledge of the career decision-making process (4 items), (b) knowledge of the self (3 items), (c) knowledge of career information (3 items), (d) anxiety towards career decision-making (3 items), and (e) career undecidedness (2 items). The CCOQ scale scores changed in the expected theoretical direction during the career counseling interventions and did not change when clients were not receiving counseling. Except for anxiety, all CCOQ subscales predicted satisfaction with the career decision twelve months after counseling. The CCOQ total score predicted satisfaction with the decision twelve months after counseling, over and beyond a widely used instrument assessing sources of career decision difficulties (i.e. the Career Decision Difficulties Questionnaire; CDDQ). Career counselors could use the CCOQ to monitor the effectiveness of their interventions in complement to diagnostic measures such as the CDDQ.