BACKGROUND Left atrial fibromuscular band (LAMB) is an infrequently described anomaly of the heart. METHODS Our knowledge about it is still limited and comes solely from case reports. RESULTS Prevalence of LAMB is nowadays estimated on 0.1 % in general population. DISCUSSION The majority of all cases appears to be completely asymptomatic and the diagnosis is made accidentally during imaging of the heart (echocardiography or computed tomography). On the contrary there is a group of patients in whom the bands are attached to mitral valve leaflet triggering mitral valve prolapse and severe regurgitation that often demand surgical repairment. Finally, the LAMB appears to be a possible cause of a cryptogenic stroke. However, this issue remains unclear cause there is not enough evidence until now.