Introduction: Diagnosis of immediate hypersensitivity reaction (HSR) for both iodinated contrast (ICM) and non ionic contrast media(NICM) is challenging based on clinical history and skin tests. Objective: The goal of this study was evaluate the negative predictive value for patients with suspected HSR to ICM and NICM doses. Methods: Standardized cases reports and clinical history of hundred and forty-one patients undergoing clinical therapy in Department of Radiology at Padre Albino Hospital from December 2015 to April 2016 were used as data collection tool to support this investigation. Results: Fourty-five from 141 patients investigated were challenged by ICM and only one patient had a positive challenge result (2.2%)which was a grade I reaction by the Ring and Messmer classification. Thirty from 45 patients evaluated were re-exposed to ICM during radiologic examination (28%) and none of them experienced a negativechallenge to ICM when a premedication or ICM replacement by NICM was applied. On the other hand, ninety six from 141 patients investigated were selected to challenge successfully NICM. Conclusions: In our study few patients had documented clinical history of immediate response to ICM and they received a premedication before re-exposure to ICM or even received ICM replacement by NICM. In conclusion, our results showed that clinical decision based on patient clinical records resulted in a decrease of several immediate reactions incidence