This study investigated the long-term efficacy and safety of empagliflozin as add-on to metformin plus sulphonylurea in patients with type 2 diabetes mellitus (T2DM). Of 666 patients treated with empagliflozin 10 mg, empagliflozin 25 mg or placebo once daily for 24 weeks, 472 patients (70.9%) were treated in a double-blind extension trial for ≥52 weeks. Pre-specified exploratory endpoints included changes from baseline in HbA(1c), weight and blood pressure at week 76. At week 76, adjusted mean differences versus placebo in change from baseline in HbA(1c) were -0.7% (-8 mmol/mol) with empagliflozin 10 mg or 25 mg (both p<0.001), in weight were -1.8 kg and -1.6 kg with empagliflozin 10 mg and 25 mg, respectively (both p<0.001), and in systolic blood pressure (SBP) were -2.2 mmHg with empagliflozin 10 mg (p=0.021) and -2.1 mmHg with empagliflozin 25 mg (p=0.029). Sensitivity analyses provided consistent results for HbA1c and weight, but showed no significant difference between empagliflozin and placebo in change from baseline in SBP. Adverse events (AEs) were reported in 81.7%, 82.0% and 81.3% of patients on empagliflozin 10 mg, 25 mg and placebo, respectively. Confirmed hypoglycaemic AEs (glucose ≤3.9 mmol/l and/or requiring assistance) were reported in 23.7%, 19.4% and 15.6% of patients on empagliflozin 10 mg, 25 mg and placebo, respectively; one patient each on empagliflozin 10mg and placebo required assistance. In conclusion, empagliflozin as add-on to metformin plus sulphonylurea for 76 weeks was well tolerated and led to sustained reductions in HbA1c and weight versus placebo. CLINICALTRIALS.GOV: NCT01289990.