Arnie Brown played most of his junior hockey with the St. Michael's Majors of the OHA where he helped his club, in the company of future NHLer Jerry Cheevers, to win the Memorial Cup in 1961.
As a Leaf prospect, the young rearguard spent most of his time sharpening his game with the Rochester Americans of the AHL until 1964. It was at that time that he was packaged up with a host of other Leaf talent and sent to the Rangers in exchange for Andy Bathgate and Don McKenney.
Brown landed his first regular NHL action with the Blueshirts in 1964-65. It was at that time that he established his game as a functional, stay-at-home rearguard who left the more dynamic play to his defensive partner, Harry Howell. In 1967, Brown served as the backdrop to Howell's Norris Trophy season as the league's top defender.
Several years later, Brown teamed up with Brad Park and put in two unprecedented seasons of offensive output. It was the heart of the Bobby Orr era when blueliners began to think and act more offensively. Brown got into the act with 36 points in 1969-70. But during the playoffs of that year, he blew out his knees, which precipitated the demise of his career. Numerous operations on both legs were required with a piece of his mobility disappearing with each intervention.
In 1971, a hobbled Brown was traded to the Detroit Red Wings for a brief dose of defensive tribulation before rounding out his NHL days with the Islanders and Flames in 1974. He then jumped to the WHA with Michigan-Baltimore and Vancouver where he retired for good in late 1974.