Background: This study was performed to evaluate the prevalence and risk factors on the adverse reactions caused by iodinated contrast media (CM) for computed tomography (CT) examination in a university hospital. Methods: Clinical and demographic data among outpatients with CM use were collected at 0000 University Busanpaik Hospital in Busan, Korea between 2008 and 2010. Adverse reaction rate was calculated by the number of adverse reaction among total outpatients with CM use, which was stratified by seasons and sex. The association of risk factors on adverse reaction was investigated using logistic regression model. Results: The total outpatients and events of administered CMs were 27,587 and 48,616, respectively. The administered CMs were iopromide, iohexol, iobitridol, and iodixanol. Adverse reactions occurred in 300 outpatients among the total outpatients (1.1 %). The number of outpatients administered CM more than twice were 8,348. Among them, outpatients who experienced adverse reaction(s) more than once and twice were 124 (1.5 %) and 26 (0.3 %), respectively. Adverse reaction rate was significantly different by sex(p=0.01). The other risk factors were cancer history (OR 2.57, 95 % CI 2.00-3.31) and previous CM administration (OR 1.89, 95 % CI 1.47-2.44). Urticaria was the most frequent symptoms. Conclusion: Total adverse reaction rate was 1.1 % with most common symptom in skin system. Related risk factors were female, cancer history, and previous CM administration. These results were similar to previous studies and will be contribute to clinical practice and future research especially in Koreans.