This study examined how the endorsement of work values changed over time and investigated the role of socioeconomic status in the development of work values. A 5-year longitudinal sample of Korean adolescents was used. Three work values were measured: Extrinsic reward, working conditions, and personal development. Findings indicate that Korean adolescents' endorsement of extrinsic reward and working conditions declines modestly over time, while no systematic change was found in the personal development value. Adolescents from a lower socioeconomic status were generally less likely to endorse work values than those from higher socioeconomic status. Implications regarding career interventions are discussed.