Clinical mentorship is a system of practical training and consultation that fosters ongoing professional development to yield sustainable high-quality clinical care outcomes.Expertise in managing antiretroviral therapy and pportunistic infections is often not found on the district management team in programmes that are starting to scale up HIV treatment.A clinical mentor in the antiretroviral therapy context is a clinician with substantial expertise in ntiretroviral therapy and opportunistic infections who can provide ongoing mentoring to less-experienced HIV clinical providers by responding to questions,reviewing clinical cases,providing feedback and assisting in case management.This mentoring occurs during site visits as well as via ongoing phone and e-mail consultation.Clinical mentoring is critical to building successful district networks of trained health care workers for HIV care and treatment in resource-constrained settings.