Telfer gained twenty one caps, and may have gained more, but for injury; as Allan Massie writes of him:
"Telfer is a man of innate authority. (There's a wealth of quiet reserve and self-knowledge, touched by that form of self-mockery which appears as under-statement, in the way he will describe himself as being a 'dominant personality')"
Telfer played back row for Scotland and for the Lions in 1966 and 1968. He was impressed and heavily influenced by New Zealand rugby. Unfortunately, after a cartilage operation he slowed up.
George Crerar said of Telfer "The great thing about Jim Telfer is that he makes sure that if he isn't going to win the ball the other side won't get it either."
He was head coach to the British and Irish Lions on their tour of New Zealand in 1983. He was assistant coach, with particular responsibility for the forwards, on the British and Irish Lions tour of South Africa in 1997.