Bulgaria, previously free from brucellosis since 1958, experienced a reemergence of human and animal brucellosis between 2005 and 2007. The study highlights the importance of maintaining active surveillance systems for infectious diseases, requiring close cooperation between public health and veterinary authorities. During this period, 34 human cases were identified, all imported, and 3 additional seropositive cases were found in dairy factory employees. In 2006, 10 human cases were reported, with 5 related to occupational risk and 5 to consumption of raw milk and dairy products. Sixteen animals were identified as seropositive and destroyed. In 2007, 58 human cases were confirmed, 54 of which were autochthonous, primarily in the Haskovo region bordering Greece and Turkey. Six hundred and twenty-five animals were also found to be seropositive and destroyed. The reemergence of brucellosis in Bulgaria is attributed to increased animal trade, occupational migration, and improved surveillance. The findings emphasize the need for health education and active surveillance to control infectious diseases and highlight the importance of cooperation between public health and veterinary officials.Bulgaria, previously free from brucellosis since 1958, experienced a reemergence of human and animal brucellosis between 2005 and 2007. The study highlights the importance of maintaining active surveillance systems for infectious diseases, requiring close cooperation between public health and veterinary authorities. During this period, 34 human cases were identified, all imported, and 3 additional seropositive cases were found in dairy factory employees. In 2006, 10 human cases were reported, with 5 related to occupational risk and 5 to consumption of raw milk and dairy products. Sixteen animals were identified as seropositive and destroyed. In 2007, 58 human cases were confirmed, 54 of which were autochthonous, primarily in the Haskovo region bordering Greece and Turkey. Six hundred and twenty-five animals were also found to be seropositive and destroyed. The reemergence of brucellosis in Bulgaria is attributed to increased animal trade, occupational migration, and improved surveillance. The findings emphasize the need for health education and active surveillance to control infectious diseases and highlight the importance of cooperation between public health and veterinary officials.