Abstract: The invention relates to the field of molecular biology and medicine, more specifically the invention is directed towards the treatment, delay and amelioration of heart diseases. More in particular, microRNAs are provided that induce cardiac regeneration by inducing cell cycle proliferation of cardiomyocytes, thereby treating or ameliorating heart diseases associated with a loss of cardiomyocytes or cardiomyocyte function. Such diseases include myocardial infarction, cardiomyopathy of ischemic or non-ischemic origin, myocarditis and heart failure. More in particular, the invention relates to a composition comprising a microRNA selected from the group consisting of microRNA 106b, microRNA 93 or microRNA 25 and the complements thereof, for use in the treatment, prevention, delay or amelioration of a heart disease.