This study cross-validated the psychometric properties of the 10-item Community Service Self-Efficacy Scale (CSSES) for evaluation of service-learning programs. Three independent samples consisting of undergraduate students and high school students were used to study the validity of the scale. An exploratory factor analysis on the scale yielded strong construct validity with a clear one-factor structure. The results from a confirmatory factor analysis indicated an excellent one-factor model fit. The internal consistency (>.89) and positive discrimination power of the scale also indicated that CSSES is a psychometrically reliable and valid instrument for evaluation of service-learning programs or research in this area for increasing community service engagement of both high school and college students.