Tanzania is a safe country to travel in.
Tanzanians are warm – hearted and generous people and are eager to help visitors get the most out of their stay. Hotels are safe and have watchmen. Tanzania is a politically stable, multi-democratic country.However, as in all countries, a little common sense goes a long way and reasonable precautions should still betaken, such as locking valuables in the hotel safe and not walking alone at night.
Source: Tanzania Tourist Board – Plan Your Trip