After being drafted by the Philadelphia Eagles in 1988, Jackson recorded 81 receptions for 869 yards, and 6 touchdowns in his first season, along with seven catches for 142 yards in the Eagles' only playoff game that year, and won the NFC Rookie of the Year award. The Eagles team record of 869 receiving yards in Jackson's rookie season was broken by DeSean Jackson in 2008, who also became the first rookie since Keith Jackson to lead the team in receptions. The two are not related.
In his nine seasons, Jackson made the Pro Bowl six times (1988–1990, 1992–1993, 1996). In his final season, Jackson made 40 receptions for 505 yards and a career-high 10 touchdowns, assisting the Green Bay Packers to a 13-3 record and a win in Super Bowl XXXI.
Jackson finished his career with 441 receptions for 5,283 yards and 49 touchdowns.
In November 2012, Jackson was named as a 2013 recipient of the NCAASilver Anniversary Award, presented each year to six distinguished former college student-athletes on the 25th anniversary of the completion of their college sports careers.