The advice comes after confirmation two of the hefty steel devices have been stolen from the Cardrona Valley this year.
Back Country Saddle Expeditions owner Debbie Thompson was the first to realise the 75kg anvil that sat outside her tack room had been stolen.
Ms Thompson this week told the Otago Daily Times she could shift her anvil but it was too heavy for her to lift.
"It's not an easy thing just to pick up and cart away.
"You've got to be a reasonable size or there's got to be a couple of people involved."
Ms Thompson said she had discussed the theft with Cardrona anvil owner and farmer Tim Scurr, who then realised his 112kg anvil was also missing.
Mr Scurr yesterday said he had bought his anvil at a sale years ago but could not remember how much he paid.
He believed whoever took it would have had to pass through his yard to get to the trees he kept it under.
He still has a similar anvil he inherited from the old "smithy" at Cardrona.
Constable Peter Reed said it appeared someone was targeting anvils in the Cardrona Valley.
He advised anvil owners to secure them and asked the public: "If you have seen anyone with an anvil, we would be keen to know."
Ms Thompson said her anvil had "sentimental value" because it had belonged to her late father Tony Hawker.
"I was a bit annoyed about it because it's actually my dad's anvil. It's about the only thing I've got to remind me of my dad.
"It's got huge sentimental value and I really don't want anyone to throw it away.
"I would actually like it back."
She had checked with scrap-metal merchants who told her they did not normally scrap anvils because the value of the metal was only about $220, while the value of an anvil was more than $2000.
