The highlight of his career at LSU came on November 9, 2002. Henderson caught the famed “Bluegrass Miracle” deep pass from Marcus Randall to help defeat the Kentucky Wildcats, 33–30. This play was also especially noteworthy as the Kentucky coach Guy Morris had already received the famed “Gatorade shower” prior to the touchdown. The “Bluegrass Miracle” also won an ESPY award the following year for “Best Play.” Henderson accepted the award on behalf of the LSU Tigers.

In 2002, Henderson recorded 23 catches for 447 yards with 8 touchdowns, carving out a role as a deep threat. Henderson was part of LSU’s 2003 BCS National Championship team during his senior season. That year, he was named on the All-SEC Second Team after racking up 11 touchdowns and 861 yards on 53 receptions.

On November 5, 2006, Devery had his best day as a professional in a game against the Tampa Bay Buccaneers, catching 3 passes for 111 yards and 2 touchdowns. Henderson had 158 receiving yards on 5 catches, including a 76-yard touchdown, against the Atlanta Falcons on November 26, 2006. On December 10, 2006, Henderson caught two passes from Drew Brees for 92 yards and one touchdown, as the Saints defeated the Dallas Cowboys 42–17 on NBC Sunday Night Football.

On March 2, 2009, Henderson re-signed with the Saints. The Saints went to the Super Bowl that year and Henderson had 7 catches for 63 yards en route to the Saints defeating the Indianapolis Colts in Super Bowl XLIV.

On September 18, 2011, Henderson had a touchdown catch for 79 yards. On October 8, 2012, he caught a touchdown pass from Drew Brees to break Johnny Unitas’s record of 47 straight games with a touchdown pass in the Saints’ 31-24 win over the San Diego Chargers.

Henderson signed with the Washington Redskins on June 12, 2013. He was released by the team on August 14, 2013.

As of 2019 he is still the #6 All-Time career Receiving Yards Leader in Saints Franchise History with 4377 yards.