Background and Objectives: Brucella is an intracellular gram-negative bacterium that can infect many kinds of mammals like humans, sheep, cattle, etc. Brucellosis is a contagious occupational disease caused by Brucella spp. that affects individuals who have close contact with infected animals. The clinical features of Brucellosis are not disease-specific and almost every organ can be affected. This zoonotic disease is a great health concern and economically important in many countries, such as Iran. The aim of this study was to detect Brucella spp. in pasteurized and non-pasteurized dairy products. Methods: In this study, 208 samples, including goat, sheep, and cow raw and pasteurized milk as well as pasteurized and nonpasteurized cheese, were collected in Tehran province. The DNA was extracted, and then the real-time PCR was used for detection of the Brucella spp. gene. Results:The prevalence of Brucella spp. contamination in the dairy products was: 45.5% in goat's raw milk, 39.1% in non-pasteurized cheese, 27.3% in sheep's raw milk, 26.3% in cow's raw milk, 25% in pasteurized cheese, and 14.7% in pasteurized milk. Conclusions: Rapid and exact detection of pathogens in dairy products is the most significant factor to prevent foodborne diseases. In addition, the real-time PCR assay is sensitive and specific enough to detect a low number of Brucella spp. in dairy products.