The answer is NO. Tanzania doesn’t allow dual citizenship. The Tanzanian Citizenship Act does not explicitly permit dual citizenship, and acquiring citizenship of another country while being a Tanzanian citizen may result in the loss of Tanzanian citizenship. However, it is always advisable to consult with the Tanzanian embassy or consulate or seek professional legal advice for the most up-to-date and accurate information regarding dual citizenship in Tanzania, as immigration and citizenship laws can be subject to change.
Tanzanian children born abroad who have gained citizenship in their home country are permitted to keep dual citizenship until the age of 21. Then, either choose one citizenship or have your Tanzanian citizenship revoked. Tanzanians who marry a foreign person and unwillingly acquire the citizenship of their spouse are permitted to keep their Tanzanian citizenship.