Medicean was described by his groom, Angela Perry as being a "quiet and lazy" horse, whilst Brough Scott called him "almost lethargically laid-back".

[5] Medicean did not race as a two-year-old: when he arrived at Stoute's stable he was described as resembling "two boards put together" and underwent an operation after developing colic.

Nine days later he recorded his first success in a minor stakes race at Sandown Park Racecourse, catching Man o' Mystery in the last stride to win by a short head.

On his next appearance, the colt moved up in distance for the John Smith's Cup, an all-aged handicap race over ten and a half furlongs at York Racecourse.

Carrying a weight of 112 pounds he started the 5/2 favourite, despite Stoute's concerns about the soft ground,[8] but made no impression in the race and finished fourteenth of the twenty-two runners.

On 2 August he finished third behind the joint-favourites Giant's Causeway and Dansili in the Group One Sussex Stakes at Goodwood Racecourse, beaten two and a quarter lengths by the winner.

At the end of the month, he returned to Goodwood for the Celebration Mile in which he was opposed by the Jersey Stakes winner Observatory and by Bachir, who had defeated Giant's Causeway in the Irish 1,000 Guineas.

Medicean moved into contention in the straight, but came under pressure and appeared to be struggling before rallying in the closing stages to win by half a length from Grandera, with Bach in third place.

[13] At York Racecourse in August Medicean started 3/1 second favourite for the International Stakes over 10+1⁄2 furlongs and finished third of the eight runners, eight lengths behind the winner Sakhee.

His major winners include:[16] 'c = colt, f = filly, g = gelding In 2017 Medicean was retired from stud duty after developing fertility problems.