['The purpose of this study was to examine energy drink (ED) usage patterns and to investigate the illicit use of prescription stimulants among college students.', 'A sample of 267 undergraduate and graduate students (mean age of 22.48 among stimulant users) from a large midwestern university and its branch campus locations voluntarily participated in the study.', 'Among prescription stimulant users without a valid medical prescription, Mann-Whitney U tests and logistic regression analysis revealed that the frequency of ED use was a significant predictor of the illicit use of prescription stimulants. Moreover, frequency of ED consumption was a significant predictor of the illicit use of prescription stimulant medications, with the odds for using increasing by .06 with each additional day of ED use past 0 day (odds for use = 1.06, P =.008).'] Does frequency of energy drink use predict illicit prescription stimulant use?