Abstract: The focus of research are the practices of mutual help in Dar es Salaam, a modern Tanzanian megapolis, serving as a substitute for (largely absent) government support. The article examines the self-organization practices of the poorest Tanzanian villagers who gravitate to the big city in search of a better life, who establish mutual help groups on the basis of trust, which replace the function of government regulation with traditional values of rural areas. Attention is drawn to the attitude of the members of such groups to legal registration and to the possibility of turning to the police in case of an internal conflict. The methods of research include immersed observation and interview, both formal and informal, conducted by O.V. Icanchenko during the expedition to Dar es Salaam in 2015. During the course of this expedition over 30 interviews were recorded with both, mutual group members and non-member citizens who are aware of such groups. Over the course of data analysis the authors come to a conclusion that the Tanzanians who moved to the city recreate the communal way of life of rural areas, but in adapted forms: neighbors and colleagues become their new environment that provides social guarantees and provides help in difficult situation instead of relatives, and the leaders of mutual help groups help resolve conflict instead of the police. Groups themselves, while emulating certain features of the government bureaucracy, still put much faith in trust, friendly neighborhood relations, and the power of moral obligations.