Current HIV management guidelines are based on natural history studies from the developed world. Data on the similarity of the natural course of HIV-1 infection conflict with studies in the developing world. A cohort of 1887 hotel workers with no access to antiretroviral therapy was followed between 1990 and 1998 in Dar es Salaam through annual clinical evaluations and CD4+ T-lymphocyte (CD4 cell) count determinations. 196 (10.4%) were HIV-1 sero-prevalents; 133 (7.9%) were HIV-1 sero-incidents; and 1558 (82.6%) remained HIV seronegative. Follow-up duration was 13,719 and 82,742 months for HIV-1 seropositives and HIV seronegatives respectively. Clinical events occurred at median CD4 cell counts similar to those previously reported from the developed world, but death occurred at higher counts. Off-duty last 6 months, chronic diarrhoea and a faster CD4 cell count decline were associated with faster disease progression and death. In Tanzania HIV natural history is similar to that from the developed world and similar management guidelines could be employed.