To design a health programme, as part of a codevelopment programme, aimed at reducing the occurrence of HIV-AIDS in a rural African population. The Catalan Society of Community and Family Medicine developed the Brothers in Work Health Programme (BWP) through a working party of Spanish and Ghanaian doctors. The programme has two consecutive stages. The first ("being safe") aims to stop transmission of the virus caused by accidents with health material. The second, intervention stage ("being active") focuses on introducing voluntary antenatal screening for HIV, counselling and a protocol for administering nevirapine to a cohort of 600 seropositive women whilst giving birth. The results will be compared with another cohort of 600 seronegative pregnant women. Three Area Hospitals in the Central Region of Ghana. 876,000 people from 3 districts. Assessment of HIV-AIDS prevalence and survival of newborns at 18 months. Monitoring of the cost-efficiency relationship of the interventions. Estimated direct costs are: a) for diagnosis of each seronegative patient, 2.43 euros (1.75 co-payment), and b) for diagnosis, counselling, and nevirapine treatment of each seropositive patient, 6.6 euros (4.65). Estimated cost-efficiency relationship of the programme is: a) for every patient diagnosed, counselled and included in the programme, 23.5 euros (15.3), and b) for each case of intra-delivery infection of baby avoided, 20.03 euros (15.5). HIV transmission to 54 children would be avoided (9% of the deliveries of seropositive women; 6.3 of the total women tested). The BWP has a good cost/benefice relationship in the interruption of HIV transmission.