AimsQishen Yiqi dripping pills (QSYQ) may be beneficial in patients with ischaemic heart failure (IHF). We aimed to assess the efficacy and safety of QSYQ administered together with guideline‐directed medical therapy in patients with IHF.Methods and resultsThis prospective randomized, double‐blind, multicentre placebo‐controlled study enrolled 640 patients with IHF between March 2012 and August 2014. Patients were randomly assigned to receive 6 months of QSYQ or placebo in addition to standard treatment. The primary outcome was 6 min walking distance at 6 months. Among the 638 IHF patients (mean age 65 years, 72% men), the 6 min walking distance increased from 336.15 ± 100.84 to 374.47 ± 103.09 m at 6 months in the QSYQ group, compared with 334.40 ± 100.27 to 340.71 ± 104.57 m in the placebo group (mean change +38.32 vs. +6.31 m respectively; P < 0.001). The secondary outcomes in composite clinical events, including all‐cause mortality and emergency treatment/hospitalization due to heart failure, were non‐significantly lower at 6 months with QSYQ compared with placebo (13% vs. 17%; P = 0.45), and the change of brain natriuretic peptide was non‐significantly greater with QSYQ compared with placebo (median change −14.55 vs. −12.30 pg/mL, respectively; P = 0.21). By contrast, the Minnesota Living with Heart Failure Questionnaire score significantly improved with QSYQ compared with placebo (−11.78 vs. −9.17; P = 0.004). Adverse events were minor and infrequent with QSYQ, similar to the placebo group.ConclusionsTreatment with QSYQ for 6 months in addition to standard therapy improved exercise tolerance of IHF patients and was well tolerated.