The potential of using mobile phones for health care service delivery has been well acknowledged. Despite that mobile health (mHealth) related research has proliferated in the past decade, mHealth is still in the fledgling stage with a low adoption rate. There is a research gap in understanding factors influencing mHealth adoption and examining the effects of mHealth use on health outcomes. The purpose of this study was thus to explore influential factors of mHealth use, and test mediation pathways through which mHealth use impacts healthy lifestyle behaviors (e.g. sleep, exercise, and social participation). Survey results from 432 online participants illustrate that performance expectancy, social influence, support conditions, and perceived reliability were significantly associated with mHealth use. However, the impact of effort expectancy on mHealth use was statistically nonsignificant. Moreover, the results indicate that mHealth use can not only contribute to the improvement of healthy lifestyle behaviors directly but also exert an impact through the mediating effect of health competence. Knowing what factors motivate people’s mHealth use and how mHealth use contributes to lifestyle improvement can help trigger interventions to boost mHealth adoption and improve public health. Implications and limitations are discussed.