The Yoruba is an age-stratified and age-disaggregated society. Age among the Yoruba is an attribute that commands respect, confers social status and responsibilities, and has social value � value that tends to appreciate the longer one lives. The effects of age permeate almost every facet of social interaction among the Yoruba. However, careful analyses of this age phenomenon among the Yoruba are rare. In this paper, I examine various ways through which age-stratification penetrates social relations among the Yoruba. I examine the cultural origins of the age-status ascription, but pay attention specifically to its role in gender relations in marriage. To do that, I examine the effects of husband-wife age gaps (the husband is typically older than his wife and hence merits his wife�s traditional respect). I also investigate the extent to which the symbolism of the marriage process and its socially �ascribed age� versus chronological age of husbands and wives within marriage unions affects marital relationships. I discuss possible explanations for why the woman typically becomes the youngest member in her marital home and the husband becomes the youngest member of his affine�s home on their marriage day. I investigate the effects of patrilocal residence (wife moving to live in close proximity to her new husband�s family) on the enforcement of the lower age rank of the wife. The complications added to age-stratification by seniority ranks and jealousy within polygynous unions are discussed. The paper concludes by discussing various ways in which modernization, Christianity and Islam, and urbanization, the media, education, etc. have affected the age-stratification among the Yoruba.