The authors investigated illicit use of stimulant medications at a midwestern university. They used a questionnaire to (a) examine the extent to which university students illicitly used stimulant medications prescribed liar attention-deficit hyperactivity disorder; (b) determine why college students abused such drugs; and (c) identify the factors that predicted illicit use of prescribed stimulant medication. Findings revealed that 17% of 179 surveyed men and 11% of 202 women reported illicit use of prescribed stimulant medication. Forty-four percent of surveyed students stated that they knew students who used stimulant medication illicitly for both academic and recreational reasons. Students reported they experienced time pressures associated with college life and that stimulants were said to increase alertness and energy. Regression analysis revealed that the factor that predicted men's use was knowing where to get easily acquired stimulant medication, whereas the main predictor for women was whether another student had offered the prescribed stimulants.Key Words: attention-deficit hyperactivity disorder, college students, illicit use, stimulant medication