T - R - O - U - B - L - E   !   . . . . . to quote Travis  Tritt.

This would be quite interesting, and why would a Seller leave it?

I would never believe that whoever lived in that house left it full with any valuables. I'd call the owners of that thing right away.

I'm with Deanna Early on this one.

Probably nothing of value if they left it!

I can probably crack that safe in less than a minute.

a gun....

I've seen larger safes that that one left behind by a seller. Of course, they were empty.

Depends on whos home it was in.

Likely nothing but I would definitely be curious and ask the listing agent.  

Call the listing Realtor.

My only thought would be to get the combination and instructions to change it!

Chris Ann Cleland Valuables.

A very small hotel room??!! 

1. Wonderful!*#. The combo was lost 17 years ago and now it is my problem.

2. The wire-rack support structure is EXCEPTIONAL.

3. Previous owner to short to reach shelf.

4. No one will be getting into my PRINGLES!

5. I think I found where the security 'disable' panel is located.

There is a certain cult in my area requires, or so it seems a common characteristic of, all members to have a home safe. Abandoned "big' safes are not uncommon.

I read the answers before answering, but would have said all paperwork but wished for gold.

Gun. Silver. Jewelry. 

My guess would be that it's either well hidden (so that the seller didn't see it when s/he was moving out) or empty (so that the seller didn't bother removing it).

Hopefully air and the combo and how to change the combo!

I would have thought it was empty. 

Either some important papers, or jewelry.  

Good morning Chris Ann. Most likely it was empty, hope they left the combination, otherwise curiosity would have been too much.

 I have no idea.

Jewelry. One of my buyers found a safe in the floor under the bed many years after their purchase. Drilling it to open they found a necklace worth over $100,000.

I'd think it would be empty, especially since it appears to have been deliberately left.  It's not as though the seller would check the closet and miss the safe. 

Chris Ann Cleland - I'd think of cash or jewelry.

Nothing, ( then I would wonder what the combination is).

I'd just take the thing to closing and give it back.  It's not like it's built in.

Probably a gun but empty now.

Important documents, I hope they left the combo for the new owners.

The big safe is often weapons. Small safe can be anything...

I would think it would be empty or they wouldnt have left it behind.... but it could also be a big surprise!!!

Chris Anne,

Probably empty.  A

Whiskey, guns, and money.

Cash but not much

Documents came to my mind.

I bet it is empty.

Stocks, bonds, and a Last Will and Testament.

Any time I see a safe that isn't in a hidden location or it's able to be easily picked up off the shelf as this one is I would not expect to find anything of value inside. 

Important papers.

Lawyers, guns and money....okay maybe not the first one. 

Jewelry

Nothing

gold

Jewelry

My thought would be jewelry. 

Family jewels!

Drugs. Or something.

Probably contains all the owners manuals and warranty info on all the home appliances, water heater, A/C etc. It's an elcheapo WalMart safe. Hubby would have that open in 10 seconds.

My 1st thought would be to call the Sellers agent and ask if they meant to leave it.