Some were last seen more than a decade ago, but the pain doesn't fade even years later for those who have no answers about where their loved ones have gone.

Missing Persons Week will run until Saturday, August 8, a bid to help offer some solace to those who have lost someone, including more than a dozen families in the Hunter.

The annual campaign is designed to raise awareness of the issues and impacts of missing people.

NSW Police Minister David Elliott said a day can feel like an eternity for those close to the case.

"With every person reported missing, there are family and friends that need to know that police will never cease in their attempt to locate their loved ones," he explained.

"If you have fears for the welfare of anyone please don't hesitate to contact the police as all information can be crucial to an investigation."

This year's event was organised by the Missing Persons Registry, part of the State Crime Command.

It comprises seven detectives and four analysts hoping to find answers for families who have waited in agony for too long.

State Crime Commander Assistant Commissioner Stuart Smith said the newly-formed registry had put 57 years of records online, including more than 760 physical files and data relating to 275 unidentified remains.

"The hard work paid off with the registry's subsequent case reviews leading to the location of 57 long-term missing people," he said.

Those on the register in the Hunter include David Webber.

Mr Webber was last seen leaving Hamilton North after stating he was going to help a friend who lived nearby. He did not reach that destination and has not been seen since.

Rhydian Trent Morgan was last seen in June 2014 in Broadmeadow, while Leslie Hinton left his home on June 13 1995 for his usual bushland walk.

He failed to return, and his car was found locked at Warners Bay.

A $1 million reward stands for information about Upper Hunter woman Janine Vaughan, who was last seen leaving a Bathurst nightclub in 2001.

A coroner found in 2009 she had died but circumstances of her death remain uncertain.

Christopher Chillingworth was last seen leaving his Hamilton home in 1996 and has not been seen since.

Michael Fowler, 55, was last seen in Williamtown in July 2015.

He had recently been diagnosed with high-level dementia and is described as about 172 centimetres tall with a thin build. He has brown hair and blue/grey eyes. He was last seen wearing a khaki coloured military style jacket and dark trousers.

They are just some of those who police will be hoping they can find answers about during the week.

Anyone who can help investigators is urged to call 1800 333 000.