After graduating from East Rutherford High School in 1940,[4] Helstoski enlisted in the United States Army Air Corps and served as an instructor and radio technician until the end of World War II in 1945.

The anti-Vietnam War Helstoski beat the nine-term Republican incumbent Frank C. Osmers Jr. by 2,428 votes to win the election, and he was sworn into the 89th United States Congress on January 3, 1965.

In the 1976 congressional elections, three-time state assemblyman Byron Baer challenged Helstoski in the Democratic primary.

He was also accused of obstruction of justice, providing a false testimony before a grand jury, and conspiracy, in order to influence other witnesses to lie.

The challenge by Baer dragged on for months, until New Jersey Superior Court Judge John Marzulli ordered that a new primary election be held on September 21.

[6] One of Helstoski's outside counsel, Alfred Porro, was indicted, convicted and sentenced to six years in the Lewisburg Federal Prison Camp.