We have a rental property in Brisbane Australia's. Our tenants moved out without giving notice, and left behind some of their belongings. How long do I have to hold their stuff before I can dispose of it. There was no lease on the property. Note to self - never rent to family again!!

Send them a letter giving them 30 days to remove their property or it will be considered abandoned. If you don't know where they moved to, send it to the last known address.

Their last address was our rental. Do I legally have to do this?

Yes, you have to show that you tried to inform them.

Legally you do. Post a letter to them at your address. I help Real Estate agents clear out deadbeat tenants items. Never once has one come back looking for their items knowing they owe you money. Personally I would donate or Craigslist the stuff in hope of some return and tell them, if they come back, "someone broke in and stole the items".

Ok thanks for your help? Will post letter and then I will donate good to a good charity