A 14-year-old boy found drunk and drug-affected at Sydney's Central station was one of 13 children detained by police in the inner city overnight.

The boy's carer thought he was in bed asleep.

Nine boys and four girls, mostly aged 14 or 15, were picked up by police on Oxford Street, George Street and around Cental Railway Station because they were unsupervised, intoxicated, under the influence of drugs or in situations that put them at risk.

But when police phoned their parents, not one of them came in from the suburbs to collect their child.

Instead, police officers drove the children home to suburbs as far away from the city as Mount Druitt, Quakers Hill, Hurstville and Earlwood.

Detective Inspector Stephen Crews said some of the parents who were contacted by police were unaware of their child's whereabouts.

"It is shocking to see so many unsupervised and underage children wandering the city streets late at night and worse still, engaging in drugs, alcohol and antisocial behaviour," he said.

"Many of the children had a blatant disregard for their own safety, let alone the safety of their friends and those around them."

Some of the parents were shocked to discover their children had lied about where they were going, he said.

Others could not be contacted when police or the children themselves tried to call.

"This is a major concern to us," Det Insp Crews said.

"Parents must make themselves contactable for their children at all times.

"We appreciate raising kids is a hard job, but parents need to take responsibility and be accountable for the actions of their children.

"The next step is for us to work closely with the Department of Community Services and see how we can support these kids.

"Each case has unique characteristics and we really do want to support them.

"The police aren't a taxi service. However, when we contact parents and carers and they're not prepared to come and collect their kids ... we have to get them home.

"I urge parents to please be a role model for their children."

NSW Police Minister Michael Gallacher said parents need to ask their children more questions about what they were up to.

"Ask more questions and make some inquiries to ensure that the knock on the door that you get at two or three o'clock in the morning isn't just a police officer returning your son or daughter home in an affected state.

"But worse, you want to make sure that the knock on the door isn't from a police officer telling you to come down to the morgue."