In 11 of 55 patients with complications of median sternotomy, a paramedian sternotomy has been detected by computed tomography or at reparative operation. The thin side of the sternum is easily broken by the closing wires, this being the cause of instability and probably dehiscence and consequent infection and osteomyelitis. Most of the 11 patients in this group had some other predisposing risk factors, such as obesity, prolonged aortic cross-clamp time, and prolonged respiratory assistance. We suggest that, if a paramedian sternotomy is diagnosed at the primary operation, special closure techniques should be undertaken. Each patient with early dehiscence of a median sternotomy should undergo a computed tomographic examination. If a paramedian sternotomy is proved, simple reclosure is inadvisable. Sternectomy and closure with muscle flaps are then indicated.