The VideoLAN Forums

i'm trying to PLAY a .MKV file on my VLC player but all i get is Audio...
is ther a plug-in or anything i can use to play this video on a MAC or a converter for any .MKV file to play on quicktime or VLC?

MKV (Matroska) is a container.
It can contain audio and video encoded with lots of different codecs. Some of them might not be supported by VLC.

You might get a more precise answer if you tell us which video codec being used.