Incidence rates of different cancers have been calculated for the population of Kyadondo county (Kampala; Uganda) for four time periods (1960-1966; 1967-1971; 1991-1994; 1995-1997); spanning 38 years in total. The period coincides with marked social and lifestyle changes and with the emergence of the AIDS epidemic. Most cancers have increased in incidence over time; the only exceptions being cancers of the bladder and penis. Apart from these; the most common cancers in the early years were cervix; oesophagus and liver; all three have remained common; with the first two showing quite marked increases in incidence; as have cancers of the breast and prostate. These changes have been overshadowed by the dramatic effects of the AIDS epidemic; with Kaposi's sarcoma emerging as the most common cancer in both sexes in the 1990s; and a large increase in incidence of squamous cell cancers of the conjunctiva. In the most recent period; there also seems to have been an increase in the incidence of non-Hodgkin lymphomas. So far; lung cancer remains rare. Cancer control challenge. With little improvement in the incidence of cancers associated with infection and poverty (liver; cervix; oesophagus); it must face the burden of AIDS-associated cancers; while coping with the emergence of cancers associated with Weternization of lifestyles (large bowel; breast and prostate)