BACKGROUND: Since 2004, Médecins Sans Frontières-Switzerland has provided treatment and care for people living with HIV in Dawei, Myanmar. Renal function is routinely monitored in patients on tenofovir (TDF)-based antiretroviral treatment (ART), and this provides an opportunity to measure incidence and risk factors for renal dysfunction. METHODS: We used routinely collected program data on all patients aged ≥15 years starting first-line TDF-based ART between January 2012 and December 2013. Creatinine clearance (CrCl) was assessed at base line and six-monthly, with renal dysfunction defined as CrCl < 50 ml/min/1.73 m2. We calculated incidence of renal dysfunction and used Cox regression analysis to identify associated risk factors. RESULTS: There were 1391 patients, of whom 1372 had normal renal function at baseline. Of these, 86 (6.3%) developed renal dysfunction during a median time of follow-up 1.14 years with an incidence rate of 5.4 per 100 person-years: 78 had CrCl between 30-50 ml/min/1.73 m2 and were maintained on TDF-based ART, but 5 were changed to another regimen: 4 because of CrCl <30 ml/min/1.73 m2. Risk factors for renal dysfunction included age ≥45 years, diagnosed diabetes, underlying renal disease, underweight and CD4 count <200 cells/mm3. There were 19 patients with baseline renal dysfunction and all continued on TDF-based ART: CrCl stayed between 30-49 ml/min/1.73 m2 in five patients while the remainder regained normal renal function. CONCLUSIONS: In a resource-poor country like Myanmar, the low incidence of renal toxicity in our patient cohort suggests that routine assessment of CrCl may not be needed and could be targeted to high risk groups if resources permit.