Drawing on conservation of resources theory (Hobfoll, 1989) and the model of proactive motivation (Parker, Bindl, & Strauss, 2010), this research employs experience sampling methods to examine how employees' off-job experiences during the evening relate to their proactive behavior at work the next day.A multilevel path analysis of data from 183 employees across 10 workdays indicated that various types of off-job experiences in the evening had differential effects on daily proactive behavior during the subsequent workday, and the psychological mechanisms underlying these varied relationships were distinct.Specifically, off-job mastery in the evening related positively to next-morning high-activated positive affect and role breadth self-efficacy, off-job agency in the evening related positively to next-morning role breadth self-efficacy and desire for control, and off-job hassles in the evening related negatively to next-morning high-activated positive affect; next-morning highactivated positive affect, role breadth self-efficacy, and desire for control, in turn, predicted next-day proactive behavior.Off-job relaxation in the evening related positively to nextmorning low-activated positive affect, and off-job detachment in the evening had a decreasingly positive curvilinear relationship with next-morning low-activated positive affect.However, as expected, these two types of off-job experiences and low-activated positive affect did not relate to next-day proactive behavior.