Myofibril assembly results in a regular array of identical sarcomeres in striated muscle. Sarcomere structure is conserved across the animal kingdom, which implies that the mechanisms of myofibril assembly are also likely to be conserved. Recent advances from model genetic systems and insights from stress fibre cell biology have shed light on the mechanisms that set sarcomere spacing and the initial assembly of sarcomere arrays. We propose a model of integrin-dependent cell–matrix adhesion as the starting point for myofibrillogenesis.