Recent studies demonstrate the potential of Mobile Health (mHealth) to improve quality of care and efficiency in low- and middle- income countries (LMIC). However, strong evidence of their impact, especially in large scale projects is still missing. The objective of this paper is to provide an overview about the current status of mHealth in LMIC, and to identify Requirements and possible Strategies to strength their health systems. A search in Pubmed was performed, which resulted in 427 articles. Restricting the search to review papers published during the last 5 years, 72 publications were identified and characterized, and the more relevant articles analyzing mHealth use, impact and/or adoption in LMIC from a more generic perspective were analyzed in detail. Finally, based on the literature, and complemented with the authors own reflections and experience, mHealth challenges and strategies were identified and presented according to the WHO Health Systems Framework which identifies six main lines of action to improve the performance of health systems: service delivery, health workforce, health information systems, essential medical products and technologies, health financing and governance.