Nowadays, the citizens are more aware of high-quality medical care than ever. They pay much attention to medical treatment safety, instructions from physicians, and the overall service quality performed by the hospital. To manage a hospital successfully, the important goals are to attract and then retain as many patients as possible by meeting potential demands of various kinds of the patients. In this context the decision making process is important in order to achieve a strategic decision and strategy. When the decision making problem occurs there is usually a limited number of possible alternatives but a large number of criteria according to which the optimal solution is selected. It is important to use an appropriate approach. This study presents a hybrid methodological approach based on the Decision Making Trial and Evaluation Laboratory (DEMATEL) method and Analytic Hierarchy process method to define the best allied hospital for an integrated network of outpatient service. The goal of this paper is to present a methodological approach and a practical application of hybrid method in a real case study.