A random survey was conducted to study the epidemiology of brucellosis in Punjab (India), using the 'Survey Toolbox' sampling software. A two-stage sampling procedure was adopted: in the first stage, villages were selected, and in the second the selection of animals was made. In all, 52 villages were selected randomly from a sampling frame of all the villages of Punjab. The total number of animals in these villages was 18,644, out of which 973 animals (approximately 5%) belonging to various owners were randomly selected. Serum samples collected from the animals were screened for Brucella antibodies by an avidinbiotin enzyme-linked immunosorbent assay, which showed the apparent overall prevalence of brucellosis to be 12.09% (true prevalence, 11.23%). The prevalence varied from a low of 0% to a high of 24.3% in various districts. Higher variance (0.08) was noted within villages than between different villages (0.03). The prevalence rates among buffaloes and cattle were 13.4% and 9.9%, respectively. The seroprevalence of brucellosis was found to be significantly higher (chi square = 24.50, p < 0.001) in animals with a history of abortion (33.87%) than in those without such a history (11.63%).