Methylphenidate hydrochloride (MPH) is one of the most widely available prescription stimulants. In response to an increase in stimulant treatment for Attention-Deficit/Hyperactivity Disorder, the prescription and production rates of MPH have increased dramatically in the past two decades. Given that college students and adolescents might be attracted to MPH for its attention-focusing, weight loss, or euphoric effects, there is concern that the rise in therapeutic use of MPH might also coincide with a rise in illicit (non-medical) use. After a dramatic increase in the 1990s, recent large-scale surveys of high-school students suggest that rates of illicit MPH use are either holding steady, or even decreasing in this population. Across studies, annual usage rates for secondary school students are below 5%, and lifetime usage rates remain below 7%. Among college students, self-reported rates range from 1.5% to 31% among the various surveys, with the most nationally representative study estimating annual illicit MPH usage at about 4%. Although more research is needed to corroborate findings, this review was able to begin developing a profile of individuals who might be more likely to illicitly use MPH. Among college students, available evidence suggests illicit MPH users were more likely to be white, male, affiliated with a formally organized fraternity, and more likely to use other illicit and illegal substances. The majority of college students reported that the primary reason for use was to improve academic performance. Future studies should provide more information on the motivations and subtypes of illicit MPH, especially repeated users and those diagnosed with ADHD. Research on prevention of illicit MPH or other stimulants used to treat ADHD would make major contributions to the literature.