Following the liberalisation of medical practice in Tanzania since the early 1990's, and the introduction of user fees in public hospitals in 1993, a household survey evaluated utilisation of health care in Dar es Salaam. A sample of 6,589 inhabitants was interviewed in April 1995 by means of a two-stage cluster sampling technique. Of the respondents, 32% reported some use of health care within the previous two weeks. Among these respondents, 35% had used government health services, 41% had used private services and self-treatment was chosen by 27%. The user patterns identified reveal that adults aged 15-49 years used government health service least often. Use of government services clearly decreased as the level of education, socioeconomic class and wealth status of the zone of residence of the ill person increased. Conversely in the study sample, there was an apparent tendency for people with a high level of education or belonging to a rich socio-economic class to use private facilities more often. The data also indicate that already after two years the private sector plays an important role in providing medical care and that a two-tier system of health care delivery is developing. In order to render the private sector complementary to public services, there is need for a coherent policy on legislation, development, regulation and control of private sector health services as well as a monitoring system to reinforce the policies.