Queensland's Department of Primary Industries said all 16 horses on the three properties quarantined near Bowen, in North Queensland, have proved negative.
Test results on the 10 people potentially exposed to the virus have also been negative, with first results from the other four still awaited.
All horses on the affected properties will remain under quarantine until the period of virus incubation has passed and all tests have returned negative results.
The lockdown is likely to last a month.
One horse on the property at the centre of the scare died from Hendra, which is transmitted from native fruit bats to horses.
The department has been holding information sessions in the wider Bowen area to explain the disease to local residents.