Marois was short on details when she made the unexpected announcement following a business speech today.
The PQ is trailing in various polls four days before Monday's election.
Marois says the cuts would be a PQ priority even though she has not mentioned them since the election was called on March 5.
When she was asked why she is bringing up the idea right now, she replied that no one had asked her about it.
Marois suggested the tax relief would also extend to businesses and that government services and programs would not suffer as a result.
The PQ has promised a balanced budget in 2015-2016 and Marois suggested any surplus could be split between reducing taxes and maintaining or improving services.
All Quebec political leaders are criss-crossing the province in the next three days in advance of the election.