Abstract Brucellosis is perhaps the most widespread and economically important of the zoonotic diseases in tropical and subtropical regions. Its control and eradication are difficult because of many technical and other aspects of the disease. Ancient practices such as nomadism, community grazing by livestock, and modern changes toward larger animal populations and increased commerce cause additional problems. Importation of high producing livestock due to demands for additional animal protein create special difficulties. Slaughter of valuable diseased animals is often impractical. Reduction of brucellosis under most conditions is best accomplished by widespread use of vaccines. Many modifications of environment, livestock management, social customs and resources will be necessary before many countries can consider eradication programs.