This research addressed the influence employee age has on organizational justice perceptions (OJPs) and organizational citizenship behaviors (OCBs) through conscientiousness. Given the valuable contributions of older employees in the workforce, the aim of this study was to investigate the processes by which age affects justice perceptions, the expression of conscientiousness traits, and workplace behaviors. Additionally, a theoretical framework was provided where the conservation of resource, equity, fairness, socioemotional selectivity, and conscientiousness at work theorieshelp explain the linkages from the integrative model. A total of 179 MTurk workers participated in this study, which required participants to answer questions about their workplace perceptions and behaviors. The primary scales used in this study measuring OJPs, conscientiousness, and OCBs were obtained from previous studies that found these measures to be reliable and valid. Using those scales, three main hypotheses were tested: Hypothesis 1 predicted age would moderate the relationship between OJPs and OCBs; Hypotheses 2 predicted conscientiousness would mediate the relationship between OJPs and OCBs; and Hypothesis 3 predicted employee age (moderating variable) would interact with justice perceptions (independent variable) and predict organizational citizenship behaviors (dependent variable), through conscientiousness (mediating variable). Results suggested that age does not moderate the relationship between OJPs and OCBs; however, conscientiousness mediates the relationship between OJPs and OCBs; and employee age only moderates the mediating effects of conscientiousness in the relationship between distributive justice perceptions and OCBs. Overall, this research provides preliminary findings to a model that had never been researched before, provides theoretical and practical implications, as well as directions for future research.