Twenty vials of anaesthetic drugs are missing from Hutt Hospital.
They were taken last Tuesday from a resuscitation bay in the hospital's emergency department.
The drugs were in liquid form stored in glass or plastic vials.
They were taken while staff were attending a patient in the resuscitation bay, Hutt Valley DHB Chief Medical Officer Sisira Jayathissa said.
"These drugs are dangerous, and could cause harm or even death if taken outside a clinical setting.