Beresfield Public School went into lockdown on Thursday morning after "an emerging situation in the community".
The school posted to its Facebook page at 9am that it was told to lock down as a precaution for the safety of staff and students.
"The situation has now been resolved and the lockdown has been ended," the school's Facebook post said.
"There will be an assembly held to explain the situation to students and ensure all understand what happened and that they are safe."
NSW Police confirmed that emergency services were called to a school in the area about 8.40am on June 6 in relation to a concern for welfare.
A NSW police spokesperson said there were no injures and no ongoing threat as a result of the matter.
