Dilated cardiomyopathy (DCM) of genetic origin represents about 25% of all so-called primary DCM. Cases due to mutation of the gene which codes the lamins A and C (LMNA) carry a poor prognosis with a high risk of sudden death. The finding of primary DCM in a young person associated with conduction defects or arrhythmias should lead to investigation for mutation of the gene of lamins A and C, even in the absence of a suggestive family history. The authors report 5 cases of DCM, with and without associated skeletal muscular disease, due to laminopathies.