Aims and MethodsBrucellosis is worldwide one of the most prevalent zoonotic diseases with serious public health hazard affecting domestic livestock and causing economic losses. Objective of this study is to estimate the true prevalence of brucellosis in livestock, specifically cattle, sheep, goats and camels, using a novel Bayesian latent class model, adjusting for the imperfect sensitivity and specificity of the applied tests, where the second test was restricted only to first test‐positive samples.ResultsBrucellosis seems more prevalent in goats and sheep, while the posterior medians and 95% probability intervals (95% PI) for the average true prevalence for sheep, goats, cattle and camels are 18% (4%–43%), 19% (7%–37%), 16% (5%–34%) and 18% (1%–48%) respectively.ConclusionsThe study results indicate that brucellosis is highly endemic in Iran and crucial steps are needed to control and raise awareness about the high public health concern of the disease.