In 1999, he caught 34 passes for 357 yards and three touchdowns, earning First-team Freshman All-American honors from The Sporting News and SEC coaches.

He was a First-team All-SEC selection by the Associated Press and SEC coaches in his final year of 2001 when he started nine of the ten games in which he appeared and had 24 receptions for 281 yards and a touchdown.

McMichael made his NFL debut in a starting role against the Detroit Lions on September 8, when he tied for team-lead with four receptions and led the team with 73 yards.

No Dolphins tight end had produced as many stats as McMichael had since Troy Drayton in 1997 (39 receptions, 558 yards, 4 touchdowns).

McMichael's four touchdown catches were the third-highest figure by a Dolphins rookie at any position, and the most by a tight end, surpassing Ferrell Edmunds, who had three in 1988.

McMichael emerged as one of the top receiving tight ends in the league in his second NFL season, starting all 16 games and finishing with 49 receptions for 598 yards and two touchdowns.

McMichael had his most productive game of the season and one of the top receiving days ever by a Dolphins tight end against the New England Patriots on October 19, when he caught eight passes for 102 yards.

His 73 receptions and 791 receiving yards both represent single-season standards for a Dolphins tight end, as he surpassed the previous marks set by Keith Jackson in 1994.

On average, it ranked slightly behind the deal signed by fellow tight end Todd Heap of the Baltimore Ravens around the same time.

The Dolphins' offense struggled as a whole in 2006, and like Chris Chambers, McMichael was not consistently and often utilized by quarterback Joey Harrington.

[4] The deal reunited McMichael with Scott Linehan, the Dolphins' 2005 offensive coordinator and then head coach of the Rams.

McMichael suffered a season-ending right tibia injury against Buffalo on September 8, 2008, and missed the rest of the 2008 NFL season, after posting 11 catches for 139 yards.

On November 7, 2010, McMichael got his first start in two years due to star tight end Antonio Gates being injured in a game against the Houston Texans he caught two catches that went for touchdowns, San Diego went on to win 29–23.

[5] In May 2019, Randy McMichael began co-hosting a midday program with Andy Bunker on sports-talk "92.9 The Game" WZGC in Atlanta.