Three representative 2-stage cluster sample surveys on sexual risk behavior and its correlates were conducted in Djibouti City and selected urban sites in Ethiopia and Sudan during 1994-95. The analysis in this paper is based on data collected from adults aged 15-49 on topics concerning marriage and regular partnerships (i.e., lasting 12+ months), nonregular sexual partnerships in the preceding 12 months, condom use, and related topics. In Djibouti City and urban sites in Ethiopia, about 10% of males reported 1 or more nonregular partnerships in the last 12 months, compared with 3% in Sudan. Between 20 and 30% of most recent nonregular contacts involved payment of money. Men with no schooling are less likely to report nonregular partnerships than other men in all 3 populations. Less than 5% of females in all 3 populations reported a nonregular partner in the preceding 12 months, but in all settings, the level is higher in divorced, separated, and widowed women. Condom use during the most recent sex act with nonregular partner ranges from 70% in Djibouti to 50% in Ethiopia and 20% in Sudan. In Sudan, the survey results suggest that the risks of rapid spread of HIV/STDs in the general population are low in Khartoum and the town of El Fashir but much higher in El Gadaif, where there is a large refugee population. In Djibouti and urban Ethiopia, risks are more generalized. Because of the lengthening interval between sexual debut and marriage, single males emerge as a priority group and further efforts are badly needed to promote condom use among the less educated.