Objectives: To describe the tolerance to long-term telavancin therapy among inpatients as it relates to nephrotoxicity. Methods: Retrospective cohort study of adult patients who received telavancin at the Barnes-Jewish Hospital from 1 September 2009 to 1 December 2010. Patients who received less than three doses of telavancin, were on haemodialysis prior to telavancin administration or died within 48 h of initial telavancin administration were excluded. Results: Twenty-one patients received telavancin and met the inclusion criteria. Seven of 21 patients (33%) developed acute renal insufficiency during therapy. Patients who developed acute renal insufficiency had a mean glomerular filtration rate reduction of 56 mL/min/1.73 m 2. In the univariate analysis, high body mass index (P = 0.025), use of intravenous contrast dye (P = 0.017) and prior serum vancomycin trough levels >20 mg/L (P = 0.017) were associated with developing acute renal insufficiency. Two patients required haemodialysis; two had persistent renal insufficiency. Conclusions: Supratherapeutic vancomycin trough levels, high body mass index and receipt of intravenous contrast dye prior to telavancin therapy were associated with acute renal insufficiency. © The Author 2011. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.