Introduction: Cancer is one of the leading causes of non-violent death in the world. An estimated eleven million new cases occur worldwide every year, of which 80% occurred in developing countries.

Objective: To determine the prevalence of cancer in a population affiliated to a health care insurance organization in Colombia.

Materials and Methods: A descriptive cross-sectional study was conducted on a cohort of 11,500 patients with cancer affiliated to a health care organization. The patients were identified from the information systems of the company, during the years 2010-2013. Data were analysed using frequencies, rates, and prevalence ratio.