Wearable self-tracking devices become increasingly common in our society and reflect the trend towards the digitized individual. However, little is known what drives the continuance and dis-continuance usage of such devices. To empirically analyze factors leading to continuance and discontinuance of wearable self-tracking device usage, we develop a conceptual model based on established post-adoption concepts and the dual-factor theory. We validate it by applying structural equation modeling on collected survey data among 357 self-tracking users. Whereas previous research focuses on predicting continuance intentions, our results reveal discontinu-ance to be another decisive determinant of usage behavior. Additionally, we provide insights into factors driving continuance and discontinuance intentions and derive practical implications for producers. Our results advance the theoretical discourse on IS post-adoption behavior in a personal ICT context.