Its roots go back to 1939, as the Quebec branch of the Co-operative Commonwealth Federation (later the New Democratic Party, NDP).
In November 1963, Quebec sovereigntists left to form the Parti socialiste du Québec (PSQ), including former leader Chartrand.
In 1989, the NPDQ voted to disaffiliate from the federal NDP as a result of policy differences, such as the provincial party's opposition to the Meech Lake Accord; its support for Quebec's language policy; differences with the federal party over the Canada–United States Free Trade Agreement; and its more favourable position towards Quebec nationalism.
[2][3] As a result, the NPDQ redirected its activities to the provincial level, and its members became free to adhere to any federal political party.
The federal NDP announced that they were seeking legal means to force the NPDQ to stop calling using the name "New Democratic".
After the 1994 election, the NPDQ decided to change its name to Parti de la démocratie socialiste (PDS).
As a consequence, the PDS withdrew its official party registration with the chief electoral officer and participated under the UFP banner in the Quebec general election of 2003.
In 2014, supporters of the federal NDP founded a new New Democratic Party of Quebec (NPDQ) which stood 59 candidates in the 2018 provincial election receiving 0.57% of the vote.