Abstract: Pedagogical agent research over the past decade has examined a broad range of topics. Research of pedagogical agent’s effect on the cognitive domain has, at best, produced mixed results as to whether the agent’s presence on-screen produces learning gains. The results appear to be mixed because of the vast range of possible agent features, and lack of a common control group in numerous experiments. This paper reviews the theoretical underpinnings of pedagogical agents, practical uses of pedagogical agents, as well as the conflicting empirical research results. The review concludes with the cost-effectiveness considerations and suggestions for future research.