Abstract: BACKGROUND: Internet addiction disorder is an interdisciplinary phenomenon and it has been studied from different viewpoints in terms of v arious sciences such as medicine, computer, sociology, law, ethics, and psychology. The aim of this study was to determine the association of psychiatric symptoms with Internet addiction while controlling for the effects of age, gender, marital status, and educational levels. It is hypothesized, that high levels of Internet addiction are associated with psychiatric symptoms and are specially correlated with obsessive-compulsive disorder symptoms. METHODS: In a cross-sectional study, a total number of 250 students from Isfahan’s universities were randomly selected. Subjects complet ed the demographic questionnaire, the Young Diagnostic Questionnaire (YDQ) and the Symptom Checklist-90-Revision (SCL-90-R). Data was analyzed using the multiple logistic regression method. RESULTS: There was an association between psychiatric symptoms such as somatization, sensitivity, depression, anxiety, aggression, phobias , and psychosis with exception of paranoia; and diagnosis of Internet addiction controlling for age, sex, education level, marital status, and type of universities. CONCLUSIONS: A great percentage of youths in the population suffer from the adverse effects of Internet addiction. It is necessary for psychiatri sts and psychologists to be aware of the mental problems caused by Internet addiction.