The average height of a player in the NBA is 6'7". Because basketball inherently relies on height to be closer to the rim, it can be difficult for smaller guys to succeed. Reaching the NBA despite such small heights are accomplishments in themselves, but some players were even able to excel in the league from a significantly smaller stature.
Webb is most famous for winning the 1986 Dunk Contest despite being its shortest ever competitor. He had a very NBA successful career, though, and played for 12 seasons. Webb's career averages of 9.9 points and 5.3 assists are exceptional for a fourth-round pick.
Boykins went undrafted but earned many contracts during his time in the league. He played on 10 different teams over 13 seasons, with a brief European stint in between. His career numbers of 8.9 points and 3.2 assists are modest, but he was a key rotational player during his time in the NBA.
At 5'3", Tyrone "Muggsy" Bogues is the shortest player to ever play in the NBA. He was an exceptional ball handler, passer, and defender. Bogues holds Charlotte Hornets franchise records for minutes played, assists, and steals.
Calvin Murphy (5'9")
Nate Robinson (5'9")
Damon Stoudamire (5'10")
Isaiah Thomas (5'9")