Southern and Eastern Africa Consortium for Monitoring Educational Quality (SACMEQ) is fast emerging as a globally recognized initiative in the area of the monitoring and evaluation of educational quality, and the results of its research and training have not only been used within the member countries, but elsewhere too. SACMEQ has had a presence in the whole of Southern and Eastern Africa, and has contributed to the broader debate on the quality of education at a variety of forums, such as the Southern Africa Development Community (SADC), Save the Children Alliance, the Association for the Development of Education in Africa (ADEA), UNESCO's Conference of Ministers of Education of African Member States (MINEDAF), the Forum for African Parliamentarians for Education (FAPED), and others. In this article, the author reviews SACMEQ's impact on education systems in Eastern and Southern Africa. He summarizes the limitations of cross-national studies' contribution to policy-reform processes. By examining the factors in SACMEQ's experiences that have either facilitated or hindered policy reform based on the processes and outcomes of SACMEQ's work, he concludes by providing caveats to those who have just embarked on, or wish to launch, similar initiatives in other parts of the world. (Contains 3 tables and 5 notes.)