The following is a list of the giants of the NBA. In NBA terms, giants are considered to be players that are at least 7'5" tall or taller barefoot. All barefoot heights are taken from the NBA official vital stats reference material.
1. Manute Bol
Born in: Sudan
Years Played: 1985-1995
NBA Position: Center
Height: 7'7" barefoot or 2.31 m
Weight: 230 lbs. or 104.5 kg
Bol's barefoot height was 7'6 3/4" (2.31m) as measured by the NBA, prior to when he entered the league, making him the tallest player in NBA history. He also has the largest wingspan in NBA history, at an amazing 8'6" (2.59m). Bol ended up growing another 1/4" from before he entered the NBA, to early in his NBA career, to a height of 7'7" (2.31m) barefoot.
7'7" Bol blocks a shot
2. Gheorghe Muresan
Born in: Romania
Years Played: 1993 - 2000
NBA Position: Center
Height: 7'7" barefoot or 2.31 m
Weight: 303 lbs. or 137.73 kg
Listed at 7'6 1/2" (2.30m) barefoot in Europe and the NBA, at the time he was drafted into the NBA. Muresan eventually grew another 1/2" to 7'7" (2.31m) in height barefoot. He has a gigantic 7'10" (2.39m) wingspan, the 2nd largest in NBA history.
7'7" Muresan
3. Shawn Bradley
Born in: Germany
Years Played: 1993 - 2005
NBA Position: Center
Height: 7'6" barefoot or 2.29 m
Weight: 280 lbs. or 127.27 kg
Bradley is 7'6" tall barefoot (2.29m) as measured by the NBA. He was measured at exactly 7'5 3/4" (2.28m) barefoot prior to being drafted into the NBA. He then grew another 1/4" after this and ended up at exactly 7'6" (2.29m) in height barefoot, as measured officially by the NBA. Bradley has a 7'6" (2.29m) wingspan.
7'6" Bradley
4. Yao Ming
Born in: China
Years Played: 2002 - present
NBA position: Center
Height: 7'6" barefoot or 2.29 m
Weight: 310 lbs. or 140.9 kg
In October of 2002, Yao was measured at 7'6" barefoot by NBA league officials. *Note that it has been reported in both Asia and Europe that Yao has since grown to 7'6 1/2" or 2.30m barefoot, which would actually make him the 3rd player tallest in NBA history, and just 1/2" in height shorter than Bol and Muresan. However, the last official NBA measurement from October of 2002, has not been updated, making verification impossible. Yao was measured at 7'5 1/2" (2.27m) prior to being drafted into the NBA. His 7'5" (2.26m) draft listing was a typographical error by the NBA, and later corrected to 7'5 1/2".
http://www.chron.com/cs/CDA/ssistory.mpl/sports/feigen/2179901
"Department of weights and measures
-- If the surge of Yao Ming dunks and power moves since last season makes him seem even bigger, that might be because he is.
Yao is no taller, but in one sense he has grown an inch to 7-6.
The Rockets did list Yao at 7-6 last season. But prior to the NBA draft, the NBA measured Yao at 7-5 1/2 and listed him at 7-5."
Yao was also measured at 7'5 1/2" (2.27m) at the age of 19, prior to the 2000 Summer Olympic Games in Syndey, Australia.
http://sportsillustrated.cnn.com/olympics/newswire/2000/09/18/141262065643_afp/
"SYDNEY, Sept 18 (AFP) - Members of the "Dream Team" think 20-year-old Chinese goliath Yao Ming has the skills to become China's first National Basketball Association player.
The NBA stars got their first look at the 2.27m center and his fellow big men in China's "Walking Great Wall" here Sunday and taught them a valuable lesson - it's hard to stand tall sitting on the bench in foul trouble."
Yao grew another 1/2" to 7'6" even barefoot by October of 2002. Yao's wingspan at the time of his complete growth, according to the Houston Rockets, reached 7'5" (2.26m). Giving him the shortest wingspan among the NBA giants.
7'6" Yao

7'6" Yao (in red), and 7'6" Bradley (in white), size each other up.

The Clash of The Titans
7'6" Yao (pictured left) and 7'6" Bradley (pictured right) .
5. Chuck Nevitt
Born in: US
Years Played: 1982 - 1994
NBA position: Center
Height: 7'5" barefoot or 2.26 m
Weight: 250 lbs. or 113.64 kg
Nevitt was measured by the NBA at 7'5" (2.26m) barefoot.
7'7" Bol and 7'5" Nevitt
It should be pointed out that over 90 percent of all NBA players in the modern league era are listed by their heights with shoes on. However, all NBA players have the option of being listed by either their height with shoes, or without shoes. In the cases of all 5 NBA giants above, they were listed by height without shoes.
Chuck Nevitt, Yao Ming, and Shawn Bradley, all chose to be listed by their barefoot heights. Nevitt would have been listed at 7'6" with shoes, Yao at 7'7" with shoes, and Bradley at 7'7" with shoes, had they opted to be listed by the NBA at their height with shoes on.
Bol and Muresan chose to be listed at their heights with shoes on. So Bol, who measured at 7'6 3/4" barefoot when he entered the NBA was listed at 7'7", his height with shoes, rounded down. Muresan was 7'6 1/2" when he entered the NBA, so he was then listed at 7'7", his height with shoes, rounded down. Bol grew another 1/4" to 7'7" even barefoot, and Muresan grew another 1/2" to 7'7" even barefoot as well.
Thus, their heights with shoes on, then should have been updated to 7'8" by the NBA. However, their heights were simply never updated by the NBA. So they too ended up being listed at their barefoot heights. Many people incorrectly believe that the heights for these 5 above players are their heights with shoes on, since that is how the vast majority of NBA players are listed. But in the cases of the 5 NBA giants above, they actually were/are listed by their barefoot heights.
Above players are ranked in height based on their respective wingspans.