Ab DeMarco Jr. was born February 27, 1949 in Cleveland, Ohio. The son of Ab DeMarco Sr., Ab Jr honed his skills with the NOJHA's North Bay Trappers before joining the OHA Jr. Kitchener Rangers in 1967-68.
After stints in the OHA Sr. with Ottawa and representing Canada at the World Championships in 1969, DeMarco signed as a free agent with the New York Rangers in the summer of 1969. Over the course of the next four seasons DeMarco spent most of his time with the blueshirts while seeing limited action with the CHL's Omaha Knights.
In 1972, DeMarco was selected by the Chicago Cougars in the WHA General Player Draft and in March of 1973 had his NHL rights traded to the St. Louis Blues. DeMarco stay in St. Louis was short lived as he was soon after traded to the Pittsburgh Penguins. Following another short stay in Pittsburgh, the Vancouver Canucks acquired DeMarco during the early stages of the 1974-75 NHL season. Upon his arrival on the West Coast, DeMarco set a career high for points during that season with 27. Even with a strong season with Vancouver, DeMarco found himself on the move yet again during the 1975-76 season, this time to the Los Angeles Kings. Now with his fifth NHL team, DeMarco went on to play 63 games in Los Angeles over the course of two seasons before finding himself back in the CHL with the Fort Worth Texans.
After parts of eight seasons in the NHL and traded yet again during the spring of 1977 to the Atlanta Flames, DeMarco who had his WHA rights transferred to Edmonton after the Chicago franchise folded, played one season with the Oilers before trying his hand one last time with the NHL in 1978-79. DeMarco signed as a free agent with the Boston Bruins in the fall of 1978 and went on to play a mere three games with the club before playing his last year of professional hockey in Switzerland in 1979-80.
