User involvement in information system development has long received research attention due to its significant effects on information system success. Prior studies have tended to focus on the consequences of user involvement, and in contrast, this research focuses on the factors that influence user involvement. The factors deserving more attention are perceived organizational support and personality traits that play significant roles in users’ IS related perceptions and behaviours. This in-progress research aims to explore the relationship among POS, personality traits, and user involvement. To achieve the research objectives, we developed a theoretical model that explains how perceived organizational support and the five personality traits namely: Neuroticism, Extraversion, Agreeableness, Openness, Conscientiousness influence user involvement. Further, this model explains how personality traits mediate the relationship between POS and user involvement.