Post-transcriptional modifications encompass a large group of RNA alterations that control gene expression. Methylation of the N 6 -Adenosine (m 6 A) of mRNA is a prevalent modification which alters the life cycle of transcripts. The roles that m 6 A play in regulating cardiac homeostasis and injury response are an active area of investigation, but it is clear that this chemical modification is a critical controller of fibroblast to myofibroblast transition, cardiomyocyte hypertrophy and division, and the structure and function of the extracellular matrix. Here we discuss the latest findings of m 6 A in cardiac muscle and matrix.