Raised in Queensland, he began to reach the top level nationally in the late 1970s, taking the runner-up spot at the Australian Athletics Championships behind Peter Grant in 1977. He was coached by former hurdler Gary Knoke. Brown's first international appearances came at the 1977 IAAF World Cup (sixth in the final) and the 1977 Pacific Conference Games, where he was the gold medallist at the Canberra-hosted event. He also came third in the 400 m hurdles at the AAA Championships in England that year, beaten by Rich Graybehl and Alan Pascoe.