BACKGROUND: TB is a major cause of mortality worldwide, with the highest risk in people living with HIV/AIDS (PLWHA). Isoniazid preventive therapy (IPT), in combination with antiretroviral therapy (ART), reduces the overall incidence and mortality from TB by up to 90% among PLWHA. Tanzania has limited published data on IPT coverage among PLWHA. OBJECTIVE: To investigate coverage and determinants of IPT among PLWHA receiving care in selected care and treatment clinics in Dar es Salaam, Tanzania. METHODS: An analytical cross-sectional design to study 31,480 HIV-positive adults. Proportions and comparisons were obtained using χ 2 tests, while determinants for IPT were assessed using adjusted multivariable analysis. RESULTS: The IPT coverage among eligible PLWHA was generally low (28.9%), with increased coverage over time. The determinants for IPT coverage included age >36 years, having WHO Clinical Stages 1 and 2 compared to 3 and 4, and having normal weight, or being overweight and obesity compared to underweight. CONCLUSION: IPT coverage in Dar es Salaam is very low; individuals with minor HIV disease severity were more likely to initiate IPT. This shows a possible gap in the prescribing practices among healthcare providers. More efforts to ensure IPT coverage implementation in Dar es Salaam are required.