Butterworth has sailed and been successful in many international sailing competitions, including the Admiral's Cup, the Kenwood Cup, the Sydney to Hobart Race, the Fastnet Race, the Whitbread Round The World Race and the America's Cup.
1987 was a busy year as he was the skipper of the top-ranked Admiral's Cup boat Propaganda when New Zealand won the Admiral's Cup in England after being aboard New Zealand's first America's Cup challenge in Fremantle as tactician earlier in the same year.
He was also a watch captain on Steinlager II with Peter Blake when she won the 1989-90 Whitbread Round The World Race and skipper of a Whitbread 60 (later Volvo Ocean 60) class boat in the 1993/1994 race where he was associated with Dennis Conner and Tom Whidden.
After the successful defense of the America's Cup in Auckland in 2000 the then skipper, Russell Coutts, tactician Butterworth and several other members of the New Zealand team moved to the Alinghi team. They then won the America's Cup in 2003, beating Team New Zealand 5-0 in waters near Auckland. After Russell Coutts left Alinghi in March 2005, Butterworth became skipper himself and went on to win the 2007 America's Cup in Valencia, again beating Team New Zealand, this time 5-2.
Public reaction in New Zealand to Butterworth and the other New Zealanders changing teams and moving to a Swiss team in 2000 was mixed. Some supported the move believing they were simply professional sailors who had already previously sailed in non-New Zealand campaigns in other sailing events (including Butterworth's own participation in the 1983 Australian team in the America's Cup), while many others regarded this move as a betrayal particularly since the America's Cup was - at that time - running with predominantly nationality-based teams.
Butterworth's impressive unbeaten run of 16 wins in America's Cup racing dating back to 1995 came to an end on June 24, 2007 when the defender, Alinghi, was beaten in the second race of the 2007 America's Cup by the challenger Emirates Team New Zealand.
In October 2009, Butterworth published an open letter commenting on the extensive litigation concerning the 33rd America's Cup. According to him, winning the America's Cup is akin to climbing the K2 mountain: something that only the top sportsmen in their field can achieve. He says: "Great sportsmen seek victory on the field of play, or in our sport; on the high seas. A sportsman seeking to win through the courts or through what Dennis called the 'backdoor' only demeans themselves as sportsmen and taints any victory, as well as the sport. Having challenged for and defended the America’s Cup successfully, I have always found it has been won by designing and building the fastest boat and sailing with the best team. It is hard to win, as it should be for such a trophy. Reducing the challenge might make the conquest easier, but gone is the attraction and achievement."
Butterworh was the skipper for the defending team Alinghi in the 2010 America's Cup. His yacht Alinghi 5 lost to the challenging yacht USA 17 by a considerable margin. Most observers stated that USA 17's rigid wing sail had given it a decisive advantage.
Butterworth led a campaign on NUMBERS, a 66 foot race boat designed by Alinghi Head of Design Team, Rolf Vrolijk and owned by American Daniel Meyers in 2007 and 2008 that resulted in winning; the maxi boat world championship in Sardinia, Cork Race Week in Ireland, and in the US, the New York Yacht Club annual regatta, the Palm Beach Race, the Lambert Ocean Race and the Palm Beach Race, Key West Race Week.
- Honolulu Star Bulletin 1996, August 16th
- RORC History of the Admiral's Cup
- Profile of Butterworth on the official America's Cup Website. Checked April 2008. 
- Interview with Brad Butterworth on the official Volvo Ocean Race website. Checked April 2008. 
- Queen's Birthday Honours List 1995. Department of the Prime Minister and Cabinet. Retrieved 10 January 2013.
- Butterworth, Brad. "Letter from Brad Butterworth, seven-time participant to the America’s Cup and four-time winner".