The assessment of efficiency of public hospitals in Tunisia is almost missing. Actually, the efficient utilization of existing resources becomes crucial for strengthening the healthcare delivery. The objective of this study was to measure technical efficiency of five cardiology wards, using an innovative nonparametric approach through an aggregated efficiency at patient level. It can assist practitioners to understand the underlying causes of clinical practice inefficiency. Linearized Free Disposal Hull using the non-radial input directional distance function provide a efficiency scores at the patient level and aggregate scores at ward’s level. The cardiology wards operate at high inefficiency. Through the 217-treated diagnosis' disease, 50 are the greatest sources of inefficiency. Each ward could save more than 50% of inputs used. The decision makers can ensure the optimum utilization of the available resources through a new design of the management and clinical practices of these wards. High inefficiency is due to the lack evaluation, accountability and effective management of public hospitals.