Background: Antiretroviral therapy (ART) adherence among children and adolescents living with human immunodeficiency virus (HIV) remains low and is associated with age, disclosure status, drug formulation, and palatability. Adherence in this population in the Bamenda municipality was hypothesized to be low.

Methods: This multicenter retrospective observational study analyzed longitudinal medical, pharmacy, and adherence-monitoring data from three HIV treatment centers in Bamenda (January 1, 2024–March 30, 2025). Consecutive records of patients aged ≤19 years with confirmed HIV, active ART follow-up, and ≥12 months of pill-count monitoring were eligible; 403 of 436 screened records were included. Poor adherence was defined as mean pill-count adherence <95%. Bivariable and multivariable logistic regression yielded adjusted odds ratios (aORs) with 95% confidence intervals (CIs).

Results: Poor adherence occurred in 237 participants (58.8%; 95% CI 53.9%–63.5%). It was independently associated with a non-parent caregiver (aOR 2.05, 95% CI 1.24–3.38; p = 0.005), non-urban residence (aOR 4.47, 2.70–7.40; p < 0.001), more-than-once-daily dosing (aOR 9.18, 4.83–17.44; p < 0.001), ART duration ≤10 years (aOR 1.67, 1.01–2.77; p = 0.045), and attendance at Nkwen District Hospital (aOR 4.41, 1.44–13.56; p = 0.010) or Saint Mary Soledad Hospital (aOR 3.42, 1.14–10.32; p = 0.029). Compared with monthly appointments, 2–3-month intervals were associated with lower odds of poor adherence (aOR 0.42, 0.20–0.90; p = 0.025), though this should be interpreted cautiously, as scheduling may have reflected pre-existing adherence difficulties.

Conclusion: Pediatric and adolescent ART adherence in Bamenda remains suboptimal, with caregiver-, residence-, treatment-, and facility-related barriers. Strengthening caregiver support and health service delivery may improve adherence in similar resource-limited settings.