Understanding the drivers of technology adoption remains an important organizational problem. Our research focused on a personality trait that is relevant to the adoption of technological innovation: personal innovativeness in IT (PIIT). We examined the causal pathways by which this trait affects behavioral intention by testing three alternative models based on innovation diffusion theory, the theory of planned behavior, and an integrative perspective that combines them. Data were collected from 196 hospital administrators in South Korea. The target innovation was an e-commerce purchasing system. Testing across all three models resulted in complete mediation, indicating that PIIT is a strong predictor of intended use of IT but it exerts its influence by altering the mediators. Our integrative perspective provides a more complete account of the causal mechanisms underlying the relationships as well as unique insights that cannot be obtained with a single theory driven model