Incidence data for corresponding time intervals (1983-87 to 1998-2002) are not available from any cancer registries in Africa. However, for completeness we examined data from four African registries, namely, Algeria (Setif), Mali (Bamako), Uganda (Kyadondo County), and Zimbabwe (Harare), with varying time intervals. From 1986-89 to 1998-2002, colorectal cancer incidence rates (per 100,000) tripled in Algeria (Setif), from 2.0 to 6.6 in males and from 2.3 to 6.8 in females. In contrast, rates remained stable for Mali, Uganda, and Zimbabwe (data not shown).