Abstract:In a setting of constant change and confusing terminology, telehealth continues to gain ground in both developed and developing countries within the overarching milieu of e-health. Evidence shows telehealth has been used in essentially all countries of the world, but is embedded in few. Uses and needs of telehealth vary between the developed and developing world; the latter struggles with both communicable diseases and noncommunicable diseases, and with very few resources. Common clinical applications include teleconsultation, telecardiology (transmission of ECGs), teleradiology, and teledermatology. Many telehealth projects exist throughout Latin America and the Caribbean, Asia, and Africa, but there is little published evidence and only isolated examples of sustained programs, although several sustained humanitarian networks exist. Application of mobile solutions (m-health) is on the rise in many developing countries. Telehealth is still not integrated into existing health care systems globally. Reasons vary: lack of proven large-scale operations, poor evidence base, inadequate implementation, lack of attention to the "soft side" of implementation (readiness, change management), and many others. For the developing world, reasons can be more pragmatic, including limited resources, unreliable power, poor connectivity, and high cost for the poverty stricken -those most in need. Telehealth is poised to improve health and health care in the developing world, driven by both altruistic and profit motives. But to have the desired effect, telehealth must address very specific and evidence-based health "needs" of each facility, region, or country; the shortage of health workers and specialist services; and the required skills upgrading and training, allowing the developing world to establish its own critical mass of experts. This will only be achieved by raising awareness, understanding, and ability regarding telehealth capability and limitations, and by the coordinated political and professional will of all those involved to guide public and private innovation and telehealth integration.