The American teen requested the surgery after his penis grew too large, restricting his ability to have sex or play competitive sports.
The boy's surgeons were shocked when he came to them complaining that his penis was too big.
When flaccid, it measured almost seven inches in length and had a circumference of 10 inches - around the size of a grapefruit.
The surgeon who treated the teenager, Rafael Carrion, a urologist at the University of South Florida, told MailOnline: 'There comes a time in every urologist's career that a patient makes a request so rare and impossible to comprehend that all training breaks down and leaves the physician speechless.
'That question was "can you make my penis smaller"?' The answer was YES.
The doctors were able to bypass the urethra - the tube which carries urine through the penis - and all of the nerves that provide sensation.
The teenager spent just two days in hospital before returning home, apparently 'ecstatic' with his new penis.
The doctors did not take final measurements of the penis, although Dr Carrion told MailOnline the result was 'generous'.
'It's slightly longer and slightly thicker than the average male, but now it looks symmetrical, and the patient was very satisfied,' he said.
The teen now has no problem having normal erections and has full sensation.
'It looks cosmetically appealing, and he said it was a life-changing event, he's all smiles,' said Carrion.
