Research on the effects of personality on work behaviors has adopted either the motivational meditation perspective or the person-situation interaction perspective. This study attempted to integrate both of the perspectives in a single causal model. Specifically, using data collected from systems engineers and car salespeople in Japan, we investigated the mediating role of intrinsic motivation in the links from openness and conscientiousness to continuous learning, and the moderating role of occupation on the mediation mechanism. The results indicated that, for systems engineers, the effects of those personality traits on continuous learning were completely mediated via intrinsic motivation. For car salespeople, however, the trait effects on the outcome variable are direct, rather than transmitted through intrinsic motivation. The meanings of the findings and directions for future research are discussed.