Simian hemorrhagic fever (SHF) was induced in three species of monkeys (Macaca mulatta, M. radiata and M. fascicularis) using plasma from animals that died with SHF in the 1967 outbreak at the California Primate Research Center. The disease was uniformly fatal in all three species with death occurring by day 5 in M. radiata and M. fascicularis and by day 7 in M. mulatta. Serial studies of hemostasis were consistent with the occurrence of disseminated intravascular coagulation, particularly in the M. mulatta. Studies of pathology were typical of previously reported findings in SHF and support the possibility of intravascular coagulation. The role of intravascular coagulation in the pathogenesis and outcome of SHF remains uncertain but studies of the influence of heparin on the disease are in progress.