Colston has developed into a premier wideout since being picked in the seventh round by New Orleans in the 2006 NFL draft out of Hofstra University. He has become a prime target for Saints quarterback Drew Brees.
He opened this season by making three receptions for 26 yards in last Sunday's 24-20 win against Tampa Bay.
"It's a ligament in his left thumb and basically the surgery was to stabilize the thumb," Coach Sean Payton said on the team's Web site. "It's going to take some time."
Last season, the 6-foot-4, 225-pounder established a franchise record with 11 touchdowns after 98 receptions for 1,202 yards.
In 2007, his rookie NFL season, Colston scored eight times on 70 catches for 1,038 yards.