In 1963, Larry Pleau led his midget team, the Marblehead Maroons, to the USA Midget Championship. He then played a few years in major junior hockey in Canada, with the Montreal Junior Canadiens. After playing for the US at the 1968 Winter Olympics, he played minor league hockey in 1968-69 with the Jersey Devils of the Eastern Hockey League, and then moved up to the American Hockey League with the Montreal Voyageurs in 1969-70. Pleau then played three years in the NHL with the Montreal Canadiens from 1969-72, playing a bit in 1972 with their AHL affiliated, the Nova Scotia Voyageurs. From 1972-79, Pleau played seven years with the New England Whalers of the World Hockey Association, finishing his career with a few games in 1979 with the Springfield Indians of the AHL. Pleau then went into coaching, serving as head coach of the Hartford Whalers, formerly New England and by then an NHL team, from 1980-83 and 1988-89. He also coached from 1984-87 with the Binghamton Whalers, the Whalers AHL affiliate.