ATMega168 replacement

Can I replace a defective ATMega168 on a Duemilanove-board with a ATMega328 with a bootloader for a UNO-board?
Thank you for replies

Yes.

have you searched the forum ? There are many posts on this ....

Not only Yes, but please!

The only possible reason to use a mega168 is that it may be significantly cheaper - and you know that it will remain sufficient in capability, for your purpose.

Unless you are in production, there is no reason to even look for mega168s.

As to the UNO bootloader, this is also most sensible. It means you select any board you are using as "UNO" rather than "Duemilanove" and would equally apply to a Nano.