The Bantams' first half pressure was rewarded when Jon Stead's fired City into the lead shortly before the break but two goals from Doncaster Rovers in the space of ten second half minutes gave the visitors a barely deserved away victory.
Despite the defeat though, Parkinson was encouraged by his side's efforts throughout City's latest contest against Yorkshire neighbours.
Parkinson said: "It is a really frustrating afternoon for us.
"There have been times this season when I've stood here and we probably haven't deserved anything but today (Saturday) certainly wasn't the case.
"In the first half in particular we were excellent but we perhaps lost our way a bit around the period that Steady (Jon Stead) came off.
"He got a bit of a dead-leg at the back end of the first half. He wanted to try and carry on in the second half but he clearly wasn't quite ready and it disrupted us a bit.
"All in all though, I thought we showed bravery on the ball, endeavour and work-rate off it, and we certainly deserved something out of the game.
"That moment late on in the second half when Alan Sheehan's header from a corner has hit one of our own players instead of going in just about summed our day up really.
"There is always things you can do better with every goal you concede but it has been a bit of a 'smash and grab' from Doncaster really."
While the loss for Parkinson's men was clearly not ideal for City's confidence levels, the Bantams chief feels keeping a positive outlook on things is important.
Parkinson added: "We must keep the lads as positive as possible really.
"When we haven't won at home in a bit and we are playing at home again, the bravery shown on the ball from the lads today, especially from the likes of Billy Knott and Mark Yeates, was top class.
"We have to take those positives. If you get too down on ourselves, we are never going to achieve anything.
"If the lads keep playing the way they did today, I can't complain. I think that is key.
"Obviously we know that we need results and we want those results, but when our performances levels are like they were today, I can't be too down on myself or the players.
"There were a lot of honest and committed performances today and we have to keep recreating them."
Striker Aaron Mclean missed out on the Doncaster defeat altogether after Parkinson decided not to even name the striker on the bench.
Parkinson revealed that Mclean has been made available for loan in a bid to free up some funds for the City boss to possibly use on a new recruit.
He said: "There are a few clubs who are interested in taking Aaron on loan and I've told him that I'm happy for him to go because it will give us some money to work with to bring someone else in.
"With that in mind, we felt it was best to leave Aaron out today."