This study aimed to investigate the relationship between perceived usefulness and the sustainable usage of mobile health among smartphone users in Uganda, mediated by behavioral intentions. A cross-sectional and quantitative design was used, employing correlation, regression, and mediation analysis to achieve the study objectives. Data were collected through survey questionnaires from 366 smartphone users in Eastern Uganda. The formulated objectives and hypotheses were analyzed using the SPSS tool. The findings revealed that perceived usefulness is positively correlated with the sustainable usage of mobile health. Mediation analysis showed that behavioral intentions partially mediate the relationship between perceived usefulness and mobile health usage. This study is one of the first to explore the mediating role of behavioral intentions in this context. It is relevant to academics, the government of Uganda, health regulatory organizations, and medical alliances, as mobile health offers a viable option for citizens to access and disseminate healthcare information. It demonstrates that behavioral intention contributes to the relationship between perceived usefulness and mobile health usage, providing evidence for policymakers to consider these factors when developing strategies to strengthen mobile health usage and ensure its long-term viability. This study presents a new model suggesting that perceived usefulness predicts behavioral intentions, which, in turn, enhances continued usage of mobile health. Additionally, it confirms that behavioral intentions partially mediate the relationship between perceived usefulness and mobile health usage, an area previously unexplored in the context of Uganda for healthcare access and dissemination.