Tenofovir disoproxil fumarate (TDF) is a nucleotide reverse transcriptase inhibitor discovered in the USA in 2001. It is currently the treatment of choice for patients co-infected with human immunodeficiency virus (HIV) and hepatitis B virus. Its antiretroviral efficacy and good tolerance are responsible for the higher frequency of prescriptions compared with other nucleoside analogs. However, it can induce acute renal toxicity causing impairment of the proximal tubular function of the kidney. This is highly dependent on factors such as associated co-prescription didanosine or a protease inhibitor "boosted" with ritonavir, preexisting renal insufficiency, low body weight, or presence of associated diabetes. In contrast, long-term renal toxicity remains highly debated. Some studies describe a decrease in estimated glomerular filtration rate during prolonged treatment with TDF. Others reported renal safety even during prolonged use. The differences between patients enrolled in the different studies, the measured parameters and their interpretation could explain these discrepancies. We describe a case of a patient infected with HIV, who presented with Fanconi syndrome with acute renal failure six months after starting antiretroviral treatment including tenofovir.