Globally, the twenty-fi rst century has witnessed tremendous progress in the application of demographic methods to the study of labor force dynamics. Changes in population structure have also led to changes in labor force trends, sizes, and compositions both in the African continent and in the other regions of the world. Ruzicka (1973) wrote that the growth in the labor force sizes, together with changes in labor force age-sex structure, is closely linked with the demographic characteristics of population in any country. Changing dynamics and patterns of labor force participation in Africa, including changing demographic structures, are a source of concern for the present and future sizes and structures of the labor force in the continent. Population characteristics such as age structure, age-sex composition, population’s socioeconomic characteristics-educational attainments, population well-being, nutritional status, and so on-have enormous infl uence on labor force sizes, structures, and levels. Other important issues, such as changes relating to transition to prime age, quantum and proportion, female labor force, women as primary breadwinners, underage labor, elderly labor, and disruptions to prime ages (because of HIV/AIDS and migration), have great implications for the labor force sizes and structures.