This study determined seroprevalence against bovine leukaemia virus and investigated the risk factors with the seropositivity of the virus in dairy cattle in Bolivia. Ninety-eight farms in five different provinces in Santa Cruz Department were visited to study 1823 dairy cattle. Questionnaire interviews, blood sampling and inspection of skin were performed at each study farm. Individual-cattle sera were analysed using the agarose gel immunodiffusion (AGID) diagnostic method for the detection of antibody against bovine leukaemia virus. The overall percentage of test positive against bovine leukaemia virus was 29% (95% confidence interval: 27-31%). One percent of the study dairy cattle had the subcutaneous lesions. There were statistical differences for percentage of test positive against bovine leukaemia virus in dairy cattle between provinces (p<0.001). The seropositivity in relation to the existence of subcutaneous lesions indicated statistical significance (p = 0.023). Knowledge of the provincial difference of seropositivity against bovine leukaemia virus in dairy cattle would be used to determine the resource allocation for preventive measures in the study area. In the preventive measures, serological tests against bovine leukaemia virus for the cattle with subcutaneous lesions, which would be a potential indicator of the infection of bovine leukaemia, should be prioritised.