There are four different conceptual approaches to assess the factors that explain, condition and determine the use of health services. This article discusses the epidemiological, psychosocial, sociological and economical models. The stages and determinants of the health service use process are described and a cross study is made with each of the four models, using a contingency matrix. A holistic analysis is proposed, as a starting point, for the search of a model that will allow the identification of factors that determine the use of health services. This analysis should be used as a conceptual framework for future work on health services utilization (Rev Méd Chile 2003; 131: 445-53).