The current study explored the relation between service motivation, or the desire to serve others through one's future career, and vocational outcomes across two studies. In the first study, using a sample of 225 undergraduate students, an instrument was developed to measure service motivation that demonstrated convergent and discriminant validity, strong internal consistency reliability, and strong test-retest reliability. In the second study, with a sample of 265 undergraduate students, service motivation was found to correlate positively with career decision self-efficacy, career adaptability, and career optimism and to correlate negatively with career indecision. Post hoc analyses found career optimism to fully mediate the relationship between service motivation and career indecision. These findings suggest that students who feel a stronger desire to use their future career to serve others will be more optimistic regarding their career future. Implications for research and practice are considered. (Contains 4 tables.)