Abstract Brucellosis is a commonly diagnosed zoonosis that causes infertility and abortion in cattle, it is acquired from handling of infected animals or consuming contaminated milk or milk products. In Colombia, it belongs to the official notifiable disease list, despite its relevance little is known about the origin, epidemiology and the genetic constituents of the strains circulating in dairy farms. Here we present the draft genome of B. abortus Ba Col-B012, an isolate obtained from a female Holstein belonging to a dairy farm in Nariño, Colombia. This genome comprises 3,234,714 bp and 3018 predicted protein-encoding genes. Using comparative genomics and phylogenetic analysis, we found that the strain Ba Col-B012 clustered with known biovar 4 variants. The analysis of the core genes allowed the identification of polymorphisms only present in biovar 4 genomes, these regions are proposed as possible targets for identification by PCR. The sequencing of B. abortus Ba Col-B012 genome provides important insights to improve the diagnosis and the epidemiology of this disease and represents the first report of the biovar 4 in Colombia.