During the latter part of winter 1967, 58 cases of plague occurred in Cam Ranh City, Republic of Vietnam. Fifty-five patients had buboes, six had pneumonia, and one had septicemia. Causes of the epidemic included favorable temperature and humidity, a known infected rat population which was rapidly increasing in numbers, a high flea index, and a nonimmunized human population. In 54 of the patients, the disease developed over an eight-day period; and in 42 patients it occurred in a single compound of some 1,500 Vietnamese workers. All patients were treated with streptomycin sulfate and tetracycline hydrochloride or chloramphenicol. There were no deaths among those treated.