On August 25-26, 2014, the Instituto de Pesquisas Energ?ticas e Nucleares (IPEN) and the National Research Council of the U.S. National Academy of Sciences convened the Brazil-U.S. Workshop on Strengthening the Culture of Nuclear Safety and Security. The workshop, held on the IPEN Campus in S?o Paulo, Brazil, examined how a culture of nuclear safety and security is built and maintained within the nuclear science, technology, and industrial sectors. Participants identified opportunities for cooperation to strengthen that culture and shared research, perspectives, and practices. This report summarizes the presentation and discussion of that event.