City returned to winning ways last Sunday in the F.A Cup by defeating West Yorkshire neighbours FC Halifax Town in a televised first round tie at The Shay.
Buoyed by the much-needed victory, Parkinson feels the cup win has boosted everyone's spirits ahead of this weekend's visit to Deepdale.
He said: "We needed that win to get us going again.
"There has been a spring in everybody's step this week, but you only get that good vibe through winning games of football.
"Whether it was the league or the cup, it didn't really matter too greatly to us, it was just important to get over the line in terms of a victory."
Having started the Halifax tie as favourites, City will most probably go into the Preston fixture as the bookies' underdogs, especially given the Lilywhites' impressive home record over the course of 2014.
Simon Grayson's men, who currently sit second in Sky Bet League 1, have yet to taste defeat at home in the league this calendar year, but the Bantams have previous when it comes to upsetting the odds on the road this campaign.
Parkinson's side have put in impressive performances at Bristol City and Milton Keynes Dons already this season, picking up four points and scoring four goals in the process.
With City faced now with another away trip to a team with designs on a place in the Championship for next season, Parkinson knows that the Bantams must repeat again the same attitude and application they showed at Ashton Gate and stadiummk.
Parkinson said: "We've shown we are capable of challenging against these sides and we must take confidence from that.
"We must also remind the players of the things we did well in those games and the things that helped us get the results that we did.
"Our mentality was strong in those matches and it must be again on Saturday.
"If you look at the Halifax game, the first ten minutes we started slow and we can't afford to do that again. We will be looking for a strong mentality from the first minute to the last at Deepdale on Saturday."