Primate nonhuman and human embryonic stem (ES) cells provide a powerful model of early cardiogenesis. Furthermore, engineering of cardiac progenitors or cardiomyocytes from ES cells offers a tool for drug screening in toxicology or to search for molecules to improve and scale up the process of cardiac differentiation using high-throughput screening technology, as well as a source of cell therapy of heart failure. Spontaneous differentiation of ES cells into cardiomyocytes is, however, limited. Herein, we describe a simple protocol to commit both rhesus and human ES cells toward a cardiac lineage and to sort out early cardiac progenitors. Primate ES cells are challenged for 4 d with the cardiogenic morphogen bone morphogenetic protein 2 (BMP2) and sorted out using anti-SSEA-1 antibody-conjugated magnetic beads. Cardiac progenitor cells can be generated and isolated in 4 d using this protocol.