This paper joins central concerns in the sociology of work and the sociology of aging. Age differences in work commitment and work values are examined, as well as their work and nonwork determinants, using data from 4,567 American and 3,735 Japanese employees. Our results show that older men are more committed to work than younger men in both Japan and the United States. This pattern also holds for American women, but there are no age differences in work commitment among Japanese women. Moreover, there are greater age differences among the Japanese in the importance placed on good pay. This is consistent with the view that there has been greater cultural change in recent years in Japan than in the United States.