We assessed the prevalence of tuberculosis (TB) human immunodeficiency virus (HIV) co-infection and identified risk factors for HIV infection in smear-positive TB patients diagnosed by the TB programme in Eritrea. Of 365 notified TB patients, 220 (60.3%) could be traced and provided a blood sample that was tested. Of these, 26 (11.8%, 95%CI 7.6-16.1) were HIV-infected. Risk factors were age, urban residence and schooling level. The data indicate that, starting with the urban areas, it is time for Eritrea to introduce HIV testing of all TB patients.