Prisoners have been forced to butt out and offered eight weeks' worth of nicotine patches to cope with the strain of the new smoking ban across NSW jails.
A riot squad will remain on stand-by after the ban came into effect on Monday.
NSW is the fourth state in Australia to implement the measures.
Inmates have been given nicotine patches for free.
"The total cost for Nicotine Replacement Therapy (NRT) won't be known for some time," a Justice Health department spokesman said.
"Evidence from other jurisdictions that have gone smoke-free showed that some patients will not require the maximum available ... while others will opt to go cold turkey."
Minister for Corrections David Elliott defended the measures, saying health care costs for long-term smokers was even greater.
"This is short-term pain for long-term gain," he said.
"If this means my kids don't have to pay for smokers and their recovery in 20 years time, well I'm prepared to make that payment."
Corrective Services Commissioner Peter Severin said some prisoners had already begun NRT and day one of the smoking ban had been "business as usual".
Some inmates have handed in tobacco under a three-week amnesty, but prison staff will continue to search cells for the contraband goods, he said.
Inmates have been provided with a range of outdoor and indoor activities, including sports equipment, competitions and playing cards, as alternatives to smoking, Corrective Services said.
Former inmate and Justice Action co-ordinator Brett Collins warned last month the ban would escalate tensions in prisons, where up to 76 per cent of inmates smoke.
