Objective To evaluate the kidney safety of tenofovir (TDF) as a first-line antiretroviral drug in patients with human immunodeficiency virus infection and acquired immune deficiency syndrome (HIV/AIDS) and to analyze the risk factors for TDF nephrotoxicity.Methods Clinical data of treatment-naive adult HIV/AIDS patients were retrospectively collected from Longtan Hospital,Guangxi from September 2010 to June 2013.The estimated glomerular filtration rates (eGFR) between adults HIV/AIDS patients who maintained antiretroviral therapy (TDF/Lamivudine[3TC]/Efavirenz[EFV] and AZT/3TC/EFV groups) for one year or more were compared.The incidences of chronic kidney disease (CKD) and renal insufficiency were compared between the two groups.The categorical variables were described with the percentage (％) and compared with the chi-square test.Normal distribution data were described with mean±standard deviation and compared with Student t test.Non-normal distribution data were described with M (P25,P75) and compared with nonparametric test.The Cox hazard model was used to determine the risk factors for CKD in uni-and multivariate analyses.Results Among 441 patients enrolled in this study,232 were in TDF group,while 209 in AZT group.At baseline,the median age was 42 (32,51) years;the median weight was 55 (50,60) kg;the mean time of follow-up was (18.5±5.0)months.Eighty-three patients (18.8％) suffered from mild renal dysfunction.During the course of 24-month treatment,eGFR level in TDF group was lower than that in AZT group,with statistical significant difference (all P＜0.05).The cumulative incidences of renal hypofunction in the TDF group and AZT group were 18.8％ and 5.8％,respectively.The difference between the two groups was statistically significant (x2 =8.017,P=0.001).The cumulative incidences of CKD in the TDF and AZT groups were 3.4％ and 0.0％,respectively,with statistically significant difference (x2 =4.544,P =0.022).Age (HR=1.148,P＜0.01),the baseline eGFR (HR=4.193,P=0.002) were independent risk factors for renal toxicity.The subgroup analysis of TDF group of age ＜40,40-49,50-59,≥60 years old showed that the cumulative incidences of CKD in the four subgroups were 0,1.9％,5.4％ and 11.1％,respectively.The difference among groups was statistically significant (x2 =10.627,P =0.014).Conclusions As the first-line antiretroviral therapy,TDF can cause renal insufficiency in patients with HIV/AIDS,but the incidence of CKD is low.Age and the baseline eGFR are the independent risk factors for TDF-induced renal toxicity.The CKD incidence is significantly elevated among patients over 50 years old who exposed to TDF,especially in patients over 60 years old.