If you can gain a better interest rate on a home loan, then yes.
The industry standard ranges from a 1% to 2% gain as being acceptable. Anything more than that, and you could likely save hundreds on your mortgage payment.
Another way that refinancing could work out well for you is if you can change the terms of the loan. These include the amount of years of the loan, or the type (fixed versus adjustable).
A final reason for refinancing would be during debt consolidation – but be careful. Having less debt all around is good, but if you use home refinancing as a method of making late payments, it might turn into a bad debt loop.