Conclusion: Prevalence of detectable HIV viral-load in Kagera Region was high. Females were more likely to have detectable HVL.  Advanced age at enrollment, HIV disclosure status, mobile occupation and history of treatment interruption predicted the occurrence of detectable viral-load among HIV clients on ART. Intensifying implementation of health education to HIV clients on ART. Timely identification of associated factors and monitoring antiretroviral treatment are needed.  