Improving efficiency has become an increasingly important target for hospital managers. One of the most commonly used tools for efficiency measurement is Data Envelopment Analysis (DEA) . DEA is applied to a set of homogenous units -the so-called decision making units, DMUs- and seeks to maximize each unit’s efficiency as it is defined through the ratio of weighted sum of outputs over weighted sum of inputs. The concept behind the method is that it allows each unit to weigh production inputs and outputs in a way so as to achieve the maximum possible efficiency compared to the other units in the sample. Put differently, each unit is allowed, in essence, to consider its own production practice as best by weighting inputs and outputs in the most preferable way .