Keloid and hypertrophic scars are a result of aberrant wound healing responses within the reticular dermis. They are thought to be secondary to the formation of a disorganized extracellular matrix due to excessive fibroproliferative collagen response. Prevention of these scars focuses on avoiding elective or cosmetic procedures such as piercings in patients at high risk, reducing tension across the lesion, and decreasing the inflammatory response. Topical treatments, including tension reduction with gel sheets, inflammatory reduction with corticosteroid ointments, and combined treatment with corticosteroid-infused tapes and plasters, can reduce scarring. Liquid nitrogen is beneficial, especially when injected into the scar through intralesional cryotherapy. Corticosteroid injection is effective for prevention and treatment. OnabotulinumtoxinA appears to be superior to both fluorouracil and corticosteroid injections for treating keloids and hypertrophic scars. Advanced treatment includes laser therapies (direct ablation, postsurgical, or laser-assisted drug delivery). Surgical revisions can be successful when tension-reducing techniques are used and when combined with other treatments such as postoperative steroid injection, laser ablation, and radiation therapy. For keloid prevention, corticosteroid injections administered 10 to 14 days postsurgery is superior to injections administered before or during surgery. Radiation therapy is considered safe with low cancer risk and can be used alone or in combination with other therapies.