Guzzo ran for the Ontario legislature a second time in the provincial election of 1995, and defeated Liberal incumbent Yvonne O'Neill by about 1,500 votes in the riding of Ottawa—Rideau.
[3] The Progressive Conservatives won a majority government in this election under Mike Harris; despite being the only Tory Member of Provincial Parliament (MPP) from Ottawa, however, Guzzo was not appointed to cabinet.
[4] In the 1999 provincial election, Guzzo won re-election in the redistributed riding of Ottawa West—Nepean[5] against Liberal Rick Chiarelli and New Democratic incumbent Alex Cullen.
He was again left out of the cabinet in the parliament which followed, and became best known for a private member's bill calling for an investigation into rumours of an organized pedophile ring in Cornwall, Ontario.
Later in the year, he courted controversy by making favourable comments about former United States Senator Joseph McCarthy, and criticizing "illegal refugees" for burdening the province's taxation system.