Background Contemporary heart failure medications have led to considerable improvement in the survival of patients with heart failure. However, limited evidence is available regarding the effect of those medications in patients with idiopathic dilated cardiomyopathy (IDCM), particularly in China. We sought to analyze the trends in clinical characteristics and the prescription rate of recommended therapies and its prognostic impact in patients with IDCM. Methods From 2009 to 2016, 1441 consecutive patients (age: 55±14 years, 68% men, LVEF: 33% ± 12%) fulfilling World Health Organization criteria for IDCM were enrolled in the current retrospective cohort study. Temporal trends of baseline clinical characteristics, treatment and prognosis were analyzed, and potential influential factors were explored. Results Rates of patients receiving angiotensin-converting enzyme inhibitors/angiotensin II receptors blockers, β-blockers, aldosterone receptor antagonists and diuretics increased from 55%, 45%, 58%, 51% in 2009 to 67%, 69%, 71%, 64% in 2016, respectively (P P P Conclusions An improvement in prescription rates of guideline-recommended medications in IDCM patients was observed. However, it remains suboptimal, and there is still some room for improvement. The prognosis of patients with optimal GDMT was better than those without. Moreover, the following patient category also had an improved prognosis: patients with LVEF ≥ 40%, with device therapy, and those admitted to a cardiology ward.