Background: Keloids are benign fibroproliferative lesions characterized by abnormal collagen deposition within a skin injury. Keloid occurs as a result of an exaggerated tissue response to skin injury in a genetically-predisposed individual. Bleomycin is an anti-cancer agent that has been utilized for treating keloids and hypertrophic scars. It inhibits collagen synthesis and activates apoptosis of fibroblasts. Objective: To assess the effectiveness and the safety of bleomycin for treating keloids and hypertrophic scar. Patients and Methods: This was a prospective randomized experimental study, carried out on forty patients with keloid or hypertrophic scars. Dermatological examination included complete clinical assessment of lesions to determine the distribution, clinical variants and the extent of lesions. Assessment of keloid was done by Vancouver scar scale (VSS). The Patient and Observer Scar Assessment Scale (POSAS) were utilized to evaluate the efficacy of treatments. No recurrence was observed after six months follow up. Results: Sixty% of the patients were females. The commonest cause for lesions was surgery, there was a significant improvement in POSAS and VSS after treatment, 52.5% of the patients showed improvement percentage >75% and other 40% showed improvement percentage 50-75%, 50% of the patients had excellent satisfaction while 42.5% had good satisfaction, the most frequently reported adverse effect was hyperpigmentation. Conclusion: Bleomycin is a safe and effective method for treating keloids and hypertrophic scars.