No new cases have been reported since Christmas Day in 2007.
NSW chief veterinary officier Bruce Christie confirmed that event registration was no longer required.
"Australia is free from Equine Influenza. The NSW Department of Primary Industries has now completed the surveillance needed to convince the rest of the world that this is true and the international community is looking at Australia in wonder and amazement at what we were able to accomplish," he said.
"People from government, the horse industry, the horse-owning public and private veterinary practitioners all working together have demonstrated what co-operation, dedication and commitment can achieve."
Christie said while registration requirements were at an end, he strongly recommended that event organisers still: