The rapid growth of the Internet of Things (IoT) has given rise to many wearable devices integrated into daily life. However, achieving end-users' long-term adoption is still an issue. While wearables' technological implementation is advancing rapidly, their consequences need to be scrutinized to alleviate the concerns that threaten a strong civil and sustainable society. The purpose of this article is to investigate issues (social, ethical, and ecological) and adoption barriers related to wearable technologies from end-users' perspectives. The authors undertook a systematic literature review combined with two rounds of interviews with domain experts as well as end-users of IoT wearable devices to find relevant issues and adoption barriers. This article summarizes social, ethical, and ecological issues as well as adoption barriers of wearable technologies. These issues and adoption barriers have important implications that need to be addressed to increase the adoption and diffusion of wearable technologies.