The need for penis-enlargement surgery is rare. Surgery is typically reserved for men whose penises don't function normally because of a birth defect or injury. Although some surgeons offer cosmetic penis enlargement using various techniques, it's controversial and considered by many to be unnecessary and in some cases permanently harmful. These surgeries should be considered experimental. There aren't enough studies of penis-enlargement surgery to give an accurate picture of risks and benefits. The most widely used surgical procedure to lengthen the penis involves severing the suspensory ligament that attaches the penis to the pubic bone and moving skin from the abdomen to the penile shaft. When this ligament is cut, the penis appears longer because more of it hangs down.