Biletnikoff recorded his only 1,000-yard receiving season in 1968, when he caught 61 passes for 1,037 yards and six touchdowns. The following season, in 1969 he caught a career-high 12 receiving touchdowns. He was an AFL All-Star for the second time and earned first-team All-AFL honors from the Associated Press, the Newspaper Enterprise Association, Pro Football Writers of America, The Sporting News, Pro Football Weekly, and the New York Daily News. The AFL merged into the National Football League in 1970. In his first five seasons in the NFL, Biletnikoff was invited to four Pro Bowls.
A highly productive receiver in the postseason, Biletnikoff left the NFL as the all-time leader in postseason receptions (70), receiving yards (1,167), and receiving touchdowns (10) accumulated over 19 postseason games. He recorded over 100 receiving yards in a postseason five times. In the 1968 American Football League playoffs, he had 14 receptions for 370 yards and four touchdowns through two games. In the 1976–77 NFL playoffs, Biletnikoff recorded 13 receptions for 216 yards and a touchdown. This included four catches for 79 yards to set up three Oakland scores in the Raiders' 32–14 victory in Super Bowl XI, for which he was named Super Bowl MVP.