From the study, the following conclusions seem justified : Hypertrophic and keloid scars could occur everywhere in the body; however, the sternum is one of the commonest sites to develop hypertrophic and keloid scars especially following median sternotomy incision. The lower half of the sternotomy wound is more susceptible to develop hypertrophic and keloid scars than the upper half, regardless of the suture materials used in skin closure. This may be due to increased tension and relative mobility of the skin over the xiphoid process. In the upper half of the sternotomy wound, use of nonabsorbable monofilament suture materials like prolene reduces the incidence of development of hypertrophic and keloid scars. So, we recommend the use of this type of suture materials in skin closure to obtain better overall cosmetic results. The incidence of hypertrophic scars is higher than keloids. Both of them can occur at any age. It is apparent that females are much more affected and asking for treatment which may be due to the fact that females are much more concerned about cosmetic disfigurement than males. Keloid is more likely to affect certain races like black and darkly pigmented skinned population, while it rarely affects Caucasians and white people, and this racial factor is the most important risk factor in developing keloid scars. Application of silicone sheet following median sternotomy incisions reduces the incidence of development of hypertrophic and keloid scars. The results that were obtained with the use of silicone sheets might be worse if we didn't use silicone sheets especially in the black race. So, we recommend the use of these sheets following median sternotomy incisions as much as we can.