The star said he felt he "shouldn't be doing it" because his late friend Cilla Black had originally hosted the show.
"I thought 'This isn't right, it's so synonymous with Cilla, she should be here, not me,'" he told Radio Times.
"But then I spoke to her sons and lots of people who knew her and they said 'You have to do it, because she'd want you to do it for everyone.'"
Black, who died in August 2015, hosted the ITV dating show from 1985 until 2003.
O'Grady said the pair had bonded over their working class Liverpudlian roots.
"We knew where we were both coming from," he said. "We both knew what outside loos were. All the stereotypical stuff."
O'Grady said it was more difficult to interview contestants than celebrities.
"You're interviewing the public, so they're not as confident. You have to be easy on them."
Blind Date, which will include LGBT contestants for the first time, begins on Channel 5 on Saturday 17 June.
The original ITV version of the show involved three individuals of the same sex being introduced to the audience. They were then asked questions by a contestant of the opposite sex who could not see them - and one would be chosen to go on a date,
The new format will retain the sliding panel that conceals the contestants, the three question format and live studio audience, but will also include "thematic twists" to "breathe new life" into the series, according to Channel 5.
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Poplars Medical Practice in Low Hill was rated by Care Quality Commission (CQC) inspectors who looked at how safe, effective and well-led it was.
They inspected 45 GP surgeries across England.
Two were rated as outstanding, in Gerrards Cross, Buckinghamshire, and Oldham.
Inspectors said staff at the Hall Practice, Gerrards Cross routinely referred to national health guidelines, received appropriate training and GPs' special interests and expertise were utilised.
In Oldham, patients at Hope Citadel Healthcare rated the practice higher than others for almost all aspects of care, inspectors reported.
Five others surgeries required improvements, inspectors found.
The Low Hill surgery served more than 3,200 patients in one of the most deprived areas in the UK, the CQC said.
Inspectors found systems to manage and address risks were not properly implemented, knowledge of and reference to national guidelines was inconsistent and there were no completed audits of patient outcomes.
It was rated good in a category for caring but inspectors said it required improvement for providing responsive services.
A CQC spokesman said further measures may be taken if sufficient improvement was not visible in the coming months.
Prof Steve Field, chief inspector of general practice, said the vast majority of England's GPs provided a safe, effective, caring, responsive and well-led service.
"Patients should be able to expect high-quality and consistent care from every GP practice," he said.
"Where we have required improvement, we will expect the practice to take the necessary steps to address the issue, and we will return at a later date to check that those improvements have been made."
Practices put it into special measures got more support from NHS England to help them improve, he said.
Paul O'Grady says "it was a shock" when he first filmed the upcoming revived version of Blind Date.
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A GP surgery in Wolverhampton has been put into special measures after being rated inadequate by a healthcare watchdog.