Abstract Background The shortage of a skilled health workforce is a global crisis. International efforts to combat the crisis have shown few benefits; therefore, more country-specific efforts are required. Tanzania adopted health sector reforms in the 1990s to ensure, among other things, availability of an adequate skilled health workforce. Little is documented on how the post-reform training and deployment of medical doctors (MDs) have contributed to resolving Tanzania’s shortage of doctors. The study aims to assess achievements in training and deployment of MDs in Tanzania about 20 years since the 1990s health sector reforms. Methods We developed a human resource for health (HRH) conceptual model to study achievements in the training and deployment of MDs by using the concepts of supply and demand. We analysed secondary data to document the number of MDs trained in Tanzania and abroad, and the number of MDs recommended for the health sector from 1992 to 2011. A cross-sectional survey conducted in all regions of the country established the number of MDs available by 2011. Results By 1992, Tanzania had 1265 MDs working in the country. From 1992 to 2010, 2622 MDs graduated both locally and abroad. This translates into 3887 MDs by 2011. Tanzania needs between 3326 and 5535 MDs. Our survey captured 1299 MDs working throughout the country. This number is less than 40% of all MDs trained in and needed for Tanzania by 2011. Maldistribution favouring big cities was evident; the eastern zone with less than 30% of the population hosts more than 50% of all MDs. No information was available on the more than 60% of MDs uncaptured by our survey. Conclusions Two decades after the reforms, the number of MDs trained in Tanzania has increased sevenfold per year. Yet, the number and geographical distribution of MDs practicing in the country has remained the same as before the reforms. HRH planning should consider the three stages of health workforce development conceptualized under the demand and supply model. Auditing and improvement of the HRH database is highly recommended in dealing with Tanzania’s MD crisis.