Nowadays, using the Internet, for academic and non-academic activities, is an integral part of students' daily life. Studies showed that excessive use of the Internet has negative effects on physical and mental health. The present research was conducted in order to compare the psychological disorders of Internet addicted students and ordinary Internet users in Zabol University of medical sciences. It applied a causal-comparative method. Through applying purposive sampling method, 252 undergraduate and postgraduate students of Zabol University of Medical Sciences were selected in May 2015. Data collection was performed using standard questionnaires of Young's Internet Addiction Test and the Symptom Check List 90-Revised (SCL-90-R). Data analysis was carried out using independent t-test with SPSS21. Results indicated that the Internet addicted students, compared with ordinary Internet users had more psychological disorders. Considering the high prevalence of psychological disorders in the Internet addicted students, teaching appropriate use of the Internet to students is an important factor in controlling the Internet addiction.