Disability activists emerged as an important influence over the first decade of the new millennium in postcommunist Central and Eastern Europe, a particularly critical time for progress in human rights and services for people with mental disabilities in that part of the world. An entrenched custodial institutional infrastructure existed for children and adults with mental disabilities in communist Central and Eastern Europe between the 1940s and the fall of communism in 1989. Activists who emerged in the subsequent postcommunist era faced multiple challenges and important new opportunities in their efforts to address human rights and quality of life for citizens with mental disabilities. Critical to their efforts were new civil society freedoms that allowed for the establishment of nongovernmental organizations (NGOs), which had previously been prohibited. Those activists and NGOs tended to represent one of two distinct missions: Either a focus on human rights protection with a watch-dog function, or an emphasis on service-provision and community-based support. Across both types of activism and NGO missions, the goal to reduce the imposition of custodial institutional life on people with mental disabilities was a priority. In addition to the history of mental disability activism in postcommunist Central and Eastern Europe, this article addresses the implications for American psychologists involved in cross-cultural and international work in disability issues, and notes the challenges facing psychologists who are engaged in both activism and the profession. (PsycINFO Database Record (c) 2019 APA, all rights reserved).