Prescription Drug Misuse (PDM) among college students is a concerning public health issue in the United States. Little research has examined misuse behaviors as they occur in college students' daily lives, limiting our understanding of the context of misuse and real-time misuse predictors. The goal of my dissertation was to better understand PDM behaviors among a sample of 300 first- and second-year college students with an elevated risk of misuse. My two dissertation studies draw from the first phase of an ongoing longitudinal study on daily behaviors and health in college life. Both studies include data collected via ecological momentary assessment (EMA), a method well-suited to obtain contextual correlates of PDM in daily life and capture naturalistic experiences close to the time of misuse. The first study compared college students' reports of PDM via EMA with retrospective accounts of the same behavior over the same period using the timeline follow-back interview (TLFB). Results indicated that participants were somewhat consistent across EMA and TLFB methods when endorsing whether they had engaged in any PDM across their entire reporting period, yet agreement was not as high as predicted. Agreement was less robust for finer-grained analyses, such as assessment of misuse on particular days and examination of the behavior by drug type. The second paper incorporated assessments of in-the-moment stimulant misuse intentions and behavior, along with survey-based assessments and official grade reports, to identify academic factors across multiple levels that were uniquely associated with elevated likelihood of prescription stimulant misuse in daily life. Momentary factors such as academic events (e.g., class time, homework, studying) emerged as the strongest predictors of misuse intentions and behaviors. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]