Trypanosomiasis outbreaks of great severity, both medical and veterinary, still occur. At the present time some of these outbreaks can be contained by implementation of plans based on sound knowledge of tsetse distribution. However, for many countries such knowledge is fragmentary. For this reason the second edition of tsetse distribution maps is to be regarded as provisional only, pending the availability of more accurate data. Some of the new information that has been received since 1973 is reported. It is concluded that a programme of intensive revision is needed before it can be claimed that tsetse situation in Africa is well understood.