CONTEXT: Weight management is an effective strategy for controlling chronic disease and maintaining physical health, and research on this topic has risen dramatically over the past four decades. The present systematic literature review aimed to identify existing evidence on the efficacy of mobile health technology in facilitating weight management behaviors, such as healthy food consumption and physical activity. EVIDENCE ACQUISITION: A systematic search was conducted in Ovid MEDLINE and Ovid PsycINFO databases with the aim to identify studies published in peer-reviewed journal articles between 2012 and 2017. EVIDENCE SYNTHESIS: A total of 39 studies were analyzed in spring 2018 and are presented here in terms of participant characteristics, effective technology components, additional treatments, impact on health-related behaviors, and treatment efficacy. Indicators of study quality and social validity are also provided. CONCLUSIONS: Mobile health apps are widely considered as satisfactory, easy to use, and helpful in the pursuit of weight loss goals by patients. The potential of mobile health apps in facilitating weight loss lies in their ability to increase treatment adherence through strategies such as self-monitoring. These findings indicate that satisfactory treatment adherence and consequent weight loss and maintenance are achieved in the presence of high levels of engagement with a mobile health app. The research quality assessment of RCTs reveals a great need for following international standards both when conducting and reporting research.