North Wales Police Chief Constable Richard Brunstrom announced on Thursday that he will insist every would-be officer must sign a personal anti-racism pledge.
Mr Brunstrom said there is no room for racism in the police
The decision follows BBC documentary the Secret Policeman broadcast in October, in which trainee policemen from the north Wales force were shown making racist remarks.
One officer has resigned and another has been suspended.
Speaking to BBC Wales on Tuesday, Mr Brunstrom talks of his zero-tolerance .
"We had a very nasty shock as a result of The Secret Policeman," he said.
"We thought we had no room for racists in the police service in Britain and north Wales.
"We discovered our recruiting process had not weeded these people out, so we have got to do something different.
"We want to make it very plain indeed there is no room at all in the British police for people with racist views and tendencies.
"What I have done is put a personal letter from me - and I think it is very important I take the lead as the chief constable - in every recruiting pack.
"It basically says if you are a racist, then don't bother proceeding any further and, if you are not a racist, please sign this pledge stating this and send it back.
Mr Brunstrom admitted that very few people would admit to being racist when asked.
"At that level, it runs the risk of being cosmetic, but it is vitally important we create a culture where people who are racist feel they will not be welcome in the police and don't attempt to join in the first place," he said.
"We were physically sickened by ex-Pc Pulling's behaviour.
"It is vitally important the police are seen to be honest, to act with integrity and to be completely free of discriminatory behaviour.
"We thought - perhaps in hindsight rather complacently - we had procedures in place that would prevent people like Mr Pulling and we were simply wrong.
"That has been a common finding across the country.
"I discovered personally somebody who was, in my view, both a racist and a sexist.
"Within eight hours they were out of the organisation - that is the way
we will proceed in the future.
"It is grounds for dismissal - in appropriate circumstances
"We have a zero-tolerance procedure for racists and sexists in the police force."