SUMMARY: A total of 6234 female sex workers practicing multi-partner sexual contacts (MPSC) from 23 urban areas of the country were tested for Human Immuno deficiency Virus type 1 (HIV1) infection, in 1988. The sample size ranged from 99 persons in Moyale, to 386 in Asmara. The mean age of the individuals studied was 24.2 years (ranging from 21.5 years to 27.1 years in the different towns). The HIV-1 prevalence rates varied from 1.3% (n=318) in Massawa, to 38.1% (n=312) in Dessie town; the mean for all towns being 17%. The highest prevalence rates were found in the towns along the road from Addis Ababa to Assab, in Bahr-Dar , Dessie and Mekele. The lowest prevalence rates were recorded in three towns of northern Ethiopia. This study indicated that Hiv-1 is widely spread in the urban areas of Ethiopia affecting female sex workers mainly in the 15-29 years age group. Previous episodes of other sexually transmitted diseases, and frequent change of sexual partners were identified as possible risk factors for HIV infection. Frequent mobility of these females may have played a significant role in HIV transmission between the towns.