To compete internationally, adapt to new technologies, and attain higher levels of efficiency and productivity, a country needs a highly literate populace. However, in Kenya, literacy stands at less than 65% of the population. With such a low rate of literacy, most development is hampered. In order for Kenya to make progress in political, social, and economic development, the level of literacy has to be raised. This paper makes an important contribution in the promotion of adult literacy in Kenya and other parts of the world by identifying and discussing the pertinent barriers to participation in adult literacy programs. Barriers such as the lack of adequate resources, poverty, the HIV/AIDS pandemic, gender disparities, traditionalism, and the absence of a literacy environment are discussed. The paper also makes suggestions on how the effects of these barriers can be mitigated.