The current study recorded an overall incidence of 9.3% (76/818) of brucellosis in small ruminants in western region (Makkah and Al-Madinah), Saudi Arabia in 2012. The incidence was 14.2% (70/492) and 1.8% (6/326) in Makkah and Al-Madinah, respectively. Regarding the animal species, the incidence was 15.6% (59/377) and 3.9% (17/441) in sheep and goats, respectively. All animal sera which were positive for Brucella antibodies using Rose Bengal Test (RBT) were also positive in indirect enzyme linked immune sorbent assay (ELISA). In Makkah, the incidence of brucellosis in the human beings was 2.7% (3/113) using agglutination test. The seropositive human cases were infected most probably as a result of their close contact with living or slaughtered infected sheep and goats during their daily work. This study concluded that Brucella infection is posing threat to both animal and human health in Saudi Arabia. The existing vaccination program should be strictly implemented with numbering and recording of the vaccinated animals. Prevention of human brucellosis in Saudi Arabia will ultimately depend on the eradication of the disease in ruminant animals. Further studies for investigating the incidence of brucellosis in human beings and ruminant animals all over the country are recommended.