In Addis Ababa estimates of the size of the sex worker sub-population varied from 2,000 to 150,000, which was too wide a range to be of any help for program planning and evaluation. No attempt had ever been made to estimate the total size of the sex worker population in the city. After considering several population size estimation methods, it was decided that a census of sex workers would provide the best information for program planning and evaluation.

This sex worker census was conducted by Family Health International and the Addis Ababa Health Bureau in collaboration with Médecins Sans Frontières-Belgium, ISAPSO and several other partners in the response to AIDS in Addis Ababa including sex workers engaged in partner projects themselves. This sex worker census is one of five assessments conducted in Addis Ababa to inform efforts for an expanded and comprehensive response to AIDS in the region. Funding for these assessments was received from USAID and CDC.

The findings of the sex worker census as well as those of the other baseline assessments have already led to concerted efforts for the design of comprehensive programming, ensuring that individual activities function within referral networks and that program beneficiaries participate in the design, implementation and monitoring & evaluation of projects.