Whanganui District Health Board chief executive Russell Simpson said the hospital had enacted full lockdown procedures from about 2.30pm and staff had talked to police to assess the level of risk.
At just after 5pm, Simpson said all services had resumed and the campus had been cleared.
"We did have a few disgruntled people who couldn't get in or out, and whilst I appreciate the inconvenience to them, their safety is the main concern for us, as is the safety of our own staff.
"Most people have been understanding, but obviously we take any threats seriously.
"Everything has been de-escalated."
During the lockdown all life and limb procedures, as well as emergency care, were continued Simpson said.
Whanganui Hospital enacted a lockdown after a bomb threat. Photo / Bevan Conley
Whanganui man Peter Maskery said he had an appointment and a nurse rang to cancel.
She told him "nobody was allowed in and nobody was allowed out of the hospital".
A Whanganui Chronicle photographer on the scene said there were no police cars visible in the area at the time of the lockdown, but it was clear people couldn't get into the hospital building because the doors were not opening.
