Background Despite Antiretroviral Therapy (ART) progress, Human Immunodeficiency Virus (HIV) remains a major issue in Tanzania (4.65% prevalence). World Health Organization (WHO) introduced Enhanced Adherence Counselling (EAC) in 2016 to improve adherence, but many patients still struggle to suppress viral load after EAC. Objective This study evaluated the effectiveness of Enhanced Adherence Counselling for people living with HIV with unsuppressed viral load in Ilala, Dar es Salaam. Methods A cross-sectional study was conducted in eight Ilala Care and Treatment Clinic (CTCs), selected using multistage sampling based on patient volume, for this study, patient volume was defined as the number of CTC clients, with high-volume facilities referring to those serving more than 1000 patients. Records of patients with unsuppressed viral load (≥1000 copies/mL) in 2023 were reviewed. Data were analysed in STATA SE 14 using descriptive, ordered, and multivariable logistic regression, with significance set at p < 0.05. Results Out of 361 people living with HIV with high viral load, 86.2% enrolled in EAC and 70.9% completed it. Among completers, 68.4% achieved viral suppression. Viral load suppression was significantly associated with age and initial viral load, with younger individuals being less likely to achieve suppression, while those with lower initial viral load (VL) had a higher likelihood of suppression. Median EAC initiation time was 27 days, with most completing it within 3 months. Conclusion The study reveals gaps in transitioning people living with HIV with unsuppressed viral load to EAC enrolment and completion, undermining EAC’s effectiveness. While 68% viral load suppression among those who completed EAC is promising, low enrolment and retention into EAC may impact overall success. Further research is needed to explore barriers to full participation into EAC sessions and its impact on viral load suppression.