While fitness apps show promise to improve people’s health and well-being, studies have indicated a high dropout rate among their users. This study uses the expectation confirmation model (ECM) to examine post-adoption factors affecting continued use or dropout among users of fitness apps, with a specific focus on the impact of users’ personality traits (the “big five” traits) on the ECM model variables. We present our theoretical model and the results of our survey with 129 participants. We confirm that satisfaction, perceived usefulness, and confirmation of expectations resulting from use of fitness apps influence the continued use of the apps. Moreover, we show that conscientiousness and neuroticism, as traits, positively influence perceived usefulness. This study increases our understanding of the factors impacting continued use of fitness apps