Can a mATX board go into an ATX case?

[Coldfirex]

Simple question (hopefully) Can a mATX board go into an ATX case?

[lenzenm]

Usually. The I/O panel is the same size, you just need the proper cover plate for it. The biggest issue is whether or not there are mounting posts in the case that correspond to the ones in the motherboard; most modern after-market cases do.
S0, a qualifies yes, or 90% of the time.

[Coldfirex]

cool, thanks

[HowardDrake]

And if the mounting points don't quite match, they make standoffs that don't have to be mounted in the case, just lie against it. I have a small bag of these for just such an emergency. They've come in handy from time to time.