Introduction. Patient safety is the set of structural elements, processes, tools and methodologies based on scientifically proven evidence that tends to minimize the risk of an adverse event during the health care process. An adverse event and its counterparts can be defined as any unintended injury caused by healthcare rather than the disease process that causes delay in discharge, extended stay, disability, additional costs associated with non quality and ultimately death the patient. Objectives. Pilot test to identify signs of adverse events that occurred in the hospital service and identification of non-quality costs in a month. Methodology. Retrospective observational study. The study subjects are patients with hospital stays longer than 24 hours. We used IBEAS project methodology adapted to a six-month follow-up implementation of screening and analysis of incidence and costs of one month pilot. The data were processed through INEVAS software designed specifically for this research and Excel PivotTables. Results : We found an incidence of 47.10% Preventable Adverse Event (EAE) in the month pilot study (February 2013), with the EA associated with care (65.24 %) the most frequent in large margin, in second place were administrative problems associated with 14.44% and third place associated with nosocomial infections (10.16 %) . In story to non-quality costs represent 10 % of the total cost of the amounts billed, with the costs for services therapeutic and diagnostic support (5.9 %) which mostly affect this percentage. Conclusions: adaptations to guide screening helped identify best evidence or EA alerts, both as administrative assistance.