Police are investigating after a fire they are treating as suspicious broke out at the former workers' club in Kurri Kurri overnight.
Crews were called to the abandoned Lang Street property about 8.15pm on Wednesday after reports the structure was well alight.
Fire and Rescue NSW crews extinguished the blaze two hours later.
The club, originally opened in 1955, closed in 2017.
Administrator Greg Russell said at the time that it was a difficult decision to close the Kurri club but it was no longer feasible for it to remain open.
"The Kurri venue, while important to the community, needs too much money spent on it to be viable," he said.
"I don't like closing venues, but we had no choice.
"People only had to read the annual report to know that the club was in trouble."
Fire and Rescue Kearsley said in a statement that the building had looked like "a total loss" as crews from Newcastle and the Coalfields helped fight the flames, but their hard work managed to hold the blaze at bay.
"Unfortunately this building has been in the sights of FRNSW for a while as a high risk, and the probability of vandals and squatters setting it alight was a real concern," the brigade said in a statement.
"Although it looked like it was going to be a total loss, crews managed to gain the upper hand pretty quick due to pre-incident planning last year."
Hunter Valley Police District officers attended and established a crime scene.
That cordon remained in place overnight.
An investigation is underway into the circumstances of the fire.
Investigators are seeking to speak with anyone who saw or heard anything in the area between 7.30pm and 8.30pm.