Army action against terrorism in Pakistan led to the largest human migration in this century. About 3.4 million people (internally displaced persons, IDPs) were displaced. The authors visited all major camps and some houses in Mardan area and interviewed IDPs and doctors at these camps and areas to identify medical needs and current state of provision of medical care. This disaster largely represented displacement of millions of people (IDPs) including women and children to a new weather and environment in overcrowded refugee camps and houses. Influx of large number of displaced people created excessive burden for already deprived local health services. The medical issues and requirements for these IDPs living in camps were totally different from a disaster like earthquake. Global response to this disaster was slow and less effective. The need for a WHO coordination center for creating quick and urgent response for such kind of disasters in future is emphasized in this article.