The incident occurred at a Waimate Highway address.
Timaru CIB's Detective Matthew Kay said the man came home to a disturbed female intruder who pointed a firearm at him.
The woman then fled and stole a number of items.
Timaru CIB conducted a scene examination today and was providing support for the victim.
Police said the public should get in touch if they saw anything suspicious on State Highway One near Waimate on Sunday afternoon.