Cynomolgus monkeys (Macaca fascicularis) were experimentally infected with a wild type measles virus (MY) strain (MY-BIL). Following intratracheal inoculation with different infectious doses, the virus could be isolated from peripheral blood mononuclear cells (PBMC), lung lavage cells, and pharyngeal cells. The kinetics of the cell-associated viremia was similar in all infected animals. They developed specific serum IgM, IgG, and neutralizing antibody responses as well as MY-specific T cell-mediated immunity. Monkeys infected intratracheally or intramuscularly with the wild type MY-Edmonston or the attenuated MY-Schwartz strain showed a lower level of PBMC-associated viremia and less pronounced specific IgM responses. Nine months after infection with MY strains, all of the monkeys were protected from intratracheal reinfection with MY-BIL. This monkey model is suitable for study of new generations of vaccines and vaccination strategies for measles.