Behavioral economic theory suggests that alcohol risk is related to elevated alcohol reinforcing efficacy (demand) combined with diminished availability of reinforcing substance-free activities, but little research has examined these reward-related processes at the daily level in association with comorbid conditions that might influence behavioral patterns and reward. Young people with attention-deficit/hyperactivity disorder (ADHD) report high levels of risky drinking, and this risk may be due in part to elevated demand for alcohol and diminished engagement in enjoyable and valued substance-free activities. College student drinkers (N = 101; 48.5% female; 68.3% White; 18-22 years old) with (n = 51) and without (n = 50) ADHD completed 14 consecutive daily diaries (diary entry n = 1,414). We conducted a series of multilevel path models to examine (a) the associations among ADHD and average daily alcohol demand, substance-free enjoyment, and response contingent positive reinforcement (RCPR) for goal-directed behaviors; (b) the associations among concurrent daily alcohol demand, substance-free reinforcement, and RCPR for goal-directed behaviors and daily alcohol use and alcohol-related negative consequences; and (c) the moderating effect of ADHD on these within-day associations. ADHD was significantly associated with more daily alcohol-related negative consequences and less daily substance-free enjoyment and RCPR. Regardless of ADHD status, there were significant associations among behavioral economic risk factors and alcohol use and negative consequences, though effects differed within and between persons. There were no moderating effects of ADHD on within-person associations. Results expose areas of impairment specific to drinkers with ADHD and advance theory on ADHD and hazardous drinking. (PsycInfo Database Record (c) 2024 APA, all rights reserved).