The scope of this paper is to characterize the main barriers faced by the Colombian population when they attempt to gain access to health services. It is an observational, descriptive and exploratory study using both quantitative and qualitative techniques. It was based on the records of Petitions, Complaints, Claims and Suggestions sent to the National Department of Health of Colombia between January 2102 and June 2013. In-depth interviews were conducted with users of health services, as well as officials of the Health Promoting Companies and Outlets for Right to Health of the Health Department of Bogotá. The study is based on domains proposed by Frenk et al for effective access to health services. Users of this study found limitations starting at admission and search for care due to communication failures in accessing health services. For ongoing care services, they encountered barriers resulting from the need for authorizations, lack of availability of specialist medical appointments, surgical procedures and drug delivery. Based on the findings, the conclusion reached is that the barriers perceived by users generate negative perceptions and harmful consequences both for them and for their families.