The Corrective Services Teachers' Association says there is at least one teacher vacancy at many of the state's correctional facilities.

Former attorney general John Dowd, QC, who is president of the Community Justice Coalition, said education in prisons is vital to creating employment opportunities, encouraging rehabilitation and reducing recidivism, but is being neglected.

"Without education in the prison system, rehabilitation is even more difficult," Mr Dowd said.

Prison education officers have reported TAFE course hours being cut. Changes under the Baird government have also meant that prisoners are no longer eligible for concession rates for TAFE courses.

NSW Greens MP David Shoebridge said prisoners, including Aboriginal people, were no longer entitled to TAFE fee concessions because they were not deemed as being a disadvantaged group.

He said the government had failed to ensure Aboriginal teaching in prisons despite the disproportionate number of Aboriginal people in jails.

"Despite key recommendations from the Royal Commission into Aboriginal Deaths in Custody, Long Bay prison has over 1200 inmates and not a single Aboriginal teacher," he said.

"We know that the most effective means of reducing recidivism is providing quality adult education services in prison."

Maree O'Halloran, director of the Welfare Rights Centre, said access to vocational training was vital for prisoners being employable after release.

"It's hard enough for them to get in the workforce having been in prison," she said. "But if they gain access to the skills that TAFE brings, that gives them their best opportunity."

Ms O'Halloran, who worked as a teacher in prisons in the late 1990s, said it was short-sighted for any government to cut access to education in jails because it was the best hope for those people "and for society".

"It's the best shot that these usually young men have of coming out and making a fresh start," she said.

"We get a lot of clients who have been in prison who are needing access to social security and who obviously want to work, but they haven't got the skills and training".

Corrective Services Teachers' Association secretary Andy Tayler, who works as an education officer at the Long Bay jail complex in La Perouse, said he was short of a literacy teacher and an IT teacher within his section of the prison. He said education opportunities for the prison's remand population have also been cut.

"There are a significant number of vacancies across the system and there is no sign of them being filled," Mr Tayler said.

Each prison in NSW had between one and 12 teachers, depending on their size, and many had at least one teacher vacancy.

A spokeswoman for Corrective Services NSW said about 18 (or 10 per cent) of 180 teacher positions in NSW prisons were vacant.  The department would absorb any course costs of approved traineeships and short courses for inmates, including the TAFE cuts to concession rates.

She said Corrective Services was "actively recruiting" to fill the vacancies and to create extra teaching positions.

"There has been no cut to CSNSW 180 frontline full-time teaching positions in more than 30 prisons across metropolitan and regional NSW."

A spokesman for TAFE NSW said it has a memorandum of understanding with the Department of Corrective Services and provides a range of short vocational education and training courses.

"Specialist TAFE NSW staff are assigned to work with staff at Corrective Services to plan and coordinate the provision of the courses in each correctional centre. Some programs are targeted to Aboriginal inmates," the spokesman said.

"The Department of Corrective Services provides a range of education and vocational programs to inmates while in custody and is a registered training organisation in its own right."

Writing for the New York Times on Saturday, John J. Lennon, an inmate at the Attica Correctional Facility in the US, said education was an integral part of prison life in the early 1980s when there were 350 college degree programs for prisoners nationwide.

"It was part of the "rehabilitative era". School buildings in prisons were like satellite campuses of colleges, and federal and state grants paid prisoners' tuitions," he said.

"Today, we live in the "retributive era." The prison population has soared.

"When the colleges left, the hope did, too, and when uneducated prisoners get out, they often come back."