The low supply of medical doctors (MDs) was experienced over the last several years in most countries in the world, and the situation is worse in developing countries as it is the case in Tanzania. Though there are efforts done and some of the efforts are just on the progress in marshalling MDs to address this crisis, it has hit the brick wall. A study was conducted to identify the reasons for low supply of medical doctors specifically in the context of Tanzania as it was conducted within the Ministry of Health and Social Welfare (MoHSW) system. There are standing causes of MDs shortage, but on top of that there were new causes of physicians? shortage that reflect the ongoing shortage of MDs. The standing causes were factors included in the growing demand such as having a population growth, aging population, increased awareness, economic factors. Also a diminishing supply which consists of factors as fewer entrants, MDs migration, physician aging and attrition, changing practice styles and changing professions. The book also hints on new causes which are restraining forces considering the efforts placed by different stakeholders to embrace the situation.