He played 11 seasons with the San Diego Chargers, with whom he earned all three of his Pro Bowl selections, and was named first-team All-Pro by the Associated Press in 1980.

Joiner played college football with the Grambling Tigers and was a three-time, first-team all-conference selection in the Southwestern Athletic Conference (SWAC).

[6][7] Joiner's parents could not afford to send him to college, but his high school coach told him football would be a good way to earn a scholarship.

[2] Future NFL starter James Harris was the Tigers' primary quarterback throughout Joiner's four years at the college,[8] each of which resulted in a Southwestern Athletic Conference (SWAC) Championship.

[9] After seeing some play on both offense and defense as a freshman,[10][11] Joiner had a breakout sophomore year as a receiver; he caught 34 passes for 822 yards and 9 touchdowns,[12] and his teammates voted him the Tigers' Most Valuable Player (MVP) for the season.

[23] He was playing on offense when his rookie season was brought to an end by injury—he was tackled after making a catch in a week 7 victory over the Denver Broncos and suffered a compound fracture of the right arm.

[27] He missed the first five regular season games before returning to face the San Diego Chargers, producing 5 catches for 100 yards and scoring his first professional touchdown on a 46-yard pass from Jerry Rhome.

[32] While the Oilers struggled for much of the season, they had one of the highest ranked passing attacks in the American Football Conference (AFC) and Joiner led the team in both receiving yardage and touchdowns.

[33][34] Houston traded Joiner to Cincinnati six games into the 1972 season, on October 24; he and linebacker Ron Pritchard were sent to the Bengals in exchange for running backs Paul Robinson and Fred Willis.

"[37] Joiner said of his new team, "You come to a new situation and you may be a little scared, but everyone here has been friendly and it's been real good," adding that he found passes from the Bengals' quarterbacks to be thrown softer and to be easier to catch.

[45][46] Head coach Paul Brown was impressed by his attitude as he fought to regain fitness after the injury, saying "No man ever worked harder or gave it more to get himself back in shape.

"[47] Joiner returned to face the Cleveland Browns after missing three games but was immediately injured again; he caught a 26-yard pass on the Bengals' first play from scrimmage but suffered a fractured collar bone while being tackled and was believed to be out for the year.

[65] Joiner scored his first postseason touchdown as the Bengals came close to rallying from seventeen points behind in the final quarter—he said, "We should have won the ball game, we just ran out of time.

[88] Joiner struggled with post-surgery knee problems during the year and finished with 33 receptions, two fewer than in 1976 despite the regular season increasing from fourteen games to sixteen.

[89] The Chargers bolstered their receiving corps entering the season by using their first-round draft pick to select tight end Kellen Winslow.

[90] It was an inspirational performance with Jefferson unable to play and John Floyd, the Chargers only other receiver, being just a rookie;[91] Coryell later remembered it as "The Charlie Joiner Game.

"[22] Joiner finished second in the AFC in receptions to Baltimore's Joe Washington, his former Chargers teammate, with a career-high 72 catches covering 1,008 yards and four touchdowns.

[98] San Diego progressed to the AFC championship game, where Joiner led the team with 6 catches for 130 yards and two touchdowns, but could not prevent a 34–27 home defeat to the Raiders.

"[101] Nonetheless, he continued his career, beginning the season as the Chargers' top wide receiver due to Jefferson holding out and eventually being traded.

[102] His production decreased in the following weeks as opposing defenses double covered him,[103] but the addition of Wes Chandler to replace Jefferson relieved that pressure.

He caught 7 passes for 108 yards, including a 39-yard reception on the penultimate play of the game to set up Rolf Benirschke's game-winning 29-yard field goal.

[106] The Chargers advanced again to the conference championship, but lost 27–7 to Joiner's former team Cincinnati in a game later known as the Freezer Bowl due to frigid gameday conditions.

[115] Joiner played the full season despite cracked ribs,[116] he caught 65 passes for 960 yards and 3 touchdowns, and was voted both the most valuable and most inspirational Charger by his teammates.

Joiner passed Taylor as the career leader in receptions on November 25, 1984, breaking the mark with 6 catches for 70 yards and a touchdown in a 52–24 loss against the Steelers.

[125] He turned 39 during the course of the season and was the second-oldest active player behind Jeff Van Note of the Atlanta Falcons, as well as the oldest wide receiver in league history.

[91] Throughout his career, he was overshadowed by more glamorous receiving mates, including LeVias and Ken Burrough in Houston, Curtis in Cincinnati, and Jefferson, Chandler, and Winslow with San Diego.

[85] In addition to good health and longevity, Joiner was an intelligent player and precise pass route runner,[141][142] capable of changing direction without sacrificing speed due to a short stride and low centre of gravity.

[146][147] He became aware early in his time in San Diego that he no longer had the sprinting speed of his youth, and compensated with an improved knowledge of defenses brought on by experience.

[160] He joined Marv Levy's Buffalo Bills shortly afterwards, again serving as a wide receiver coach,[160] then moved on to take the same role with the Kansas City Chiefs in 2001.

[163] After leaving the Oilers, Joiner continued to live in Houston throughout the rest of his playing career, only moving to Rancho Bernardo in San Diego when he joined the Chargers' coaching staff.