Can dust mess up a playstation 3?

May be...

Hey, can dust mess up a Ps3?

If too much dust accumulates in the PS3's vents (located in the back, under the serial #), it might overheat and freeze up. Look in the vent every once in a while to see if there's dust. Clean it with a vacuum hose. Also, dust the PS3.

Not at first. Just for safety measures i would dust it off every few months or so when you notice it is very dirty.

if you let it become a problem then yes it can...