Introduction: Methylphenidate, as an indirect dopamine agonist, has a high potential for illicit use among college students. The current study was designed and conducted to assess the prevalence, patterns, and factors associated with the illicit methylphenidate use. Materials and Methods: In this cross-sectional study, 900 college students from the six major cities of Iran were selected using the multi-stage sampling method from June 2019 to December 2019 and were evaluated using the researcher-made information forms 1 and 2, symptom checklist 90, and adult ADHD self-report scale. Results: 261 participants reported oral illicit methylphenidate use, and only 10% of them were not diagnosed with ADHD. The most common cause of methylphenidate illicit use was improved concentration and academic performance (78.2%) and most participants got access to methylphenidate through friends and acquaintances (64.4%). Logistic regression analysis showed that marital status, education level, awareness of the legal consequences of illicit methylphenidate use, substance/medication use, history of mental health counseling, less-stigmatized attitudes towards mental illness and mental health could predict the illicit methylphenidate use. Conclusion: Considering the important role of friends and acquaintances in the supply of illegal methylphenidate, focusing on college students with ADHD and reducing their monthly allocation of methylphenidate is an effective intervention to control the illicit methylphenidate use. Moreover, improved awareness of the legal consequences of the illicit methylphenidate use, and periodic psychiatric visits to improve the mental health of college students will reduce the illicit methylphenidate use.