This study investigates the prevalence and determinants of Diabetes Mellitus (DM) among individuals co-infected with HIV and receiving Highly Active Antiretroviral Therapy (HAART) in Taraba State, Nigeria. As the intersection of HIV and DM poses significant challenges to public health, understanding the risk factors in this specific population is crucial for effective management and prevention. The study employs a cross-sectional design, involving a 411 sample of people living with HIV (PLWHIV) undergoing HAART in four hospital locations: Taraba State Specialists Hospital Jalingo, General Hospital Zing, First Referral Hospital Mutum Biyu and General Hospital Takum of Taraba State. Data collection includes anthropometric, sociodemographic information, BMI, assumed risk factors, HAART regimen, and fasting blood glucose levels measurements are used to diagnose and assess the severity of DM. The findings indicate a prevalence of DM among PLWHIV on HAART in Taraba of 16.1% higher than the general population. Age, duration of HAART, BMI and specific antiretroviral drugs were significant risk factors. These results contribute to the growing body of evidence on the epidemiology of DM in PLWHIV, emphasizing the need for tailored interventions and routine screening protocols within HIV care settings. This research expresses understanding on risk factors of DM among PLWHIV on HAART in Taraba and offers valuable recommendations for proper management of the DM/HIV comorbidities in this population