BACKGROUND: A small number of open-label or pilot studies have assessed the benefit of stem cell therapy in dilated cardiomyopathy (DCM). I report the findings of the REGENERATE-DCM trial, a double-blind, randomised, placebo-controlled trial of bone-marrow derived mononuclear cell and adjunctive granulocyte colony stimulating factor (G-CSF) administration in patients with DCM. METHODS: 60 patients with DCM were randomized into four treatment groups: intracoronary stem cell, intracoronary serum, peripheral G-CSF and peripheral placebo (saline). Apart from the placebo group, all patients received 5-days of G-CSF, with bone marrow harvest performed on Day 6 in the intracoronary group. Primary endpoint was change in left ventricular ejection fraction (LVEF) assessed by advanced cardiac imaging at 3 months. RESULTS: There was little or no difference in baseline characteristics between the groups. At 3 months, intracoronary stem cell therapy was associated with a 5.37% increase in LVEF (38.30 ±12.97 from 32.93 ±16.46 p= 0.014). This increase in LVEF in cell treated patients was associated with clear evidence of decrease in NYHA classification and improved exercise capacity. No evidence of a change in LVEF was seen in the other two treatment groups. CONCLUSION: The novel combination of G-CSF and intracoronary cell therapy led to an improvement in cardiac function and symptoms at 3 months.