This study investigates the impacts of affective evaluations of IT on IT use decisions. We propose two object-based affective evaluation constructs: perception of an IT’s capability to induce positive affect (PC-PA) and perception of the IT’s capability to induce negative affect (PC-NA). A longitudinal study shows that PC-PA and PC-NA are distinct concepts that have different effects on commonly studied IT adoption factors, perceived usefulness (PU), perceived ease of use (PEOU), and attitude toward using the IT (ATB). These effects hold true during both initial use and continued use. PC-PA influences PU, PEOU and ATB but becomes less important to PU over time, and PC-NA only influences PEOU but becomes more important to PEOU over time. The study also offers a specific instrument on measuring affective evaluations of IT and points out future research directions.