Introduction:
Tenofovir-based regimens have been recently introduced as first-line antiretroviral treatment (ART) to human immunodeficiency virus (HIV) patients in Tanzania. Limited information on HIV viral suppression and its’ associated factors exists in Tanzania since the adoption of this intervention at a public health level. The aim of the present study was to determine HIV viral suppression rate and assess its’ associated factors among patients attending Temeke Regional Referral Hospital care and treatment clinic after twelve months of using antiretroviral therapy.

Material and methods:
Hospital-based cross-sectional study was performed to assess factors associated with HIV viral suppression. Viral load suppression was defined as HIV-RNA below 50 copies/ml, and late presentation was defined in a person who presented to care and treatment facility with WHO HIV clinical stage III or IV and/or baseline CD4+ T lymphocyte count of less than 350 cells/µl.

Results:
Among the 188 participants who were interviewed, a total of 149 (79.3%) achieved viral suppression after one year of using ART. Late presentation to health facility (OR = 3.4; 95% CI: 1.6-7.4; p < 0.01) was independently associated with inability to achieve viral suppression at 12 months.

Conclusions:
HIV testing services should be strengthened in order to achieve the UNAIDS 90-90-90 target through early detection of HIV disease.