The 29-year-old Otago batsman scored 225 in his second test as an opener to post only the eighth double century by a New Zealander overseas.
It followed his half century in the drawn first test.
In reaching the magic milestone, he became only the second New Zealander to post a double century in India after the late Bert Sutcliffe - another favourite son of the South - who made 230 not out at New Delhi during the 1955-56 tour.
McCullum's innings made the match safe for New Zealand, securing a draw for the visitors.
The former keeper-batsman was finally out 30 minutes before the tea break after being at the crease for 544 minutes and facing 308 balls, and hitting 22 fours and four sixes.
With his performance McCullum, a formidable one-day and twenty/20 exponent, elevates his reputation in the longer form of the game.
Whereas in the shorter forms he is known as an inventive and muscular slasher and basher, his innings in Hyderabad was remarkable for its display of concentration, discipline and technique.
Even so, the shot with which he achieved his double century was the risky but effective scoop shot behind the wicket, which has become something of a McCullum trademark.
Batting with him at the time was Black Caps skipper Daniel Vettori, who was quick to congratulate the Kiwi batting hero.
He was finally out caught off the bowling of fast bowler Shantakumaran Sreesanth.
His innings ensures the teams will now travel to the third test in Nagpur with the series up for grabs.
