This study aimed to describe and assess the regional experience of a pediatric hematology/oncology fellowship program based in Guatemala. The Unidad Nacional de Oncología Pediátrica (UNOP) in Guatemala City, Guatemala, is the only hospital in Central America dedicated exclusively to childhood and adolescent cancer. To address the regional need for specialists, a fellowship program in pediatric hematology/oncology was launched in 2003. The UNOP fellowship program comprises 3 years of training. Although the program is based at UNOP, it also includes rotations locally and internationally to enhance clinical exposure. The curriculum is based on international standards to cover clinical expertise, research, professionalism, communication, and health advocacy. Trainees are selected according to country or facility-level need for pediatric hematologists/oncologists, with a plan for them to be hired immediately after completing their training. Forty physicians from 10 countries in Latin America have completed training. In addition, there are currently 13 fellows from five countries in training. Of the graduates, 39 (98%) are now practicing in pediatric hematology/oncology in Latin America. Moreover, many of them have leadership positions within their institutions and participate in research, advocacy, and policy making. Graduates from the UNOP program contribute to institutions by providing care for an increasing number of patients with pediatric cancer. The UNOP program is the first pediatric hematology/oncology fellowship program in the world to be accredited by Accreditation Council for Graduate Medical Education-International, an international body accrediting clinical training programs. The UNOP program has trained specialists to increase the available care for children with cancer in Latin America. This regional approach to specialist training can maximize resources and serve as a model for other programs and regions.