<p>Bovine leukosis is a disease caused by an oncogenic retrovirus that belongs to the Retroviridae family and is known for its worldwide distribution, causing great economic losses, especially in dairy farming. Few studies on the disease have been reported in Risaralda (Colombia). The objective was to determine the prevalence of the bovine leukosis virus and its association with some risk/protection factors in cattle herds from Risaralda. Blood samples were taken from 145 individuals from 6 herds in the Risaralda region, during the year 2018. DNA extraction was carried out by salting out and PCR was used to detect the provirus DNA. For each animal, the racial composition, sex, age group, origin and herd were taken in order to evaluate possible factors associated with the presence of the virus. A descriptive analysis of the information was performed, the prevalence was estimated with the 95% confidence interval, and the effect of risk/protection factors on leukosis positivity was determined by logistic regression and the odds ratio was estimated. All analyzes were done using R software. A general prevalence of 6.90% was estimated. Statistically significant differences were found for age group one (Under 5 years) and two (5 to 10 years) with respect to age group three (Over 10 years) (OR = 0.19 in both cases), indicating a higher frequency with age. This work is one of the first carried out in the department of Risaralda and provides surveillance of the disease in Colombia.</p>