What happens if you don't show for a court hearing if you were a witness?

If you have been subpoenaed to appear at trial as a witness and have been personally served with the subpoena, you are expected to appear at the proceeding. If you fail to do so, then the court could very well issue a bench warrant for your arrest. If that happens, you would then be arrested and forced to post a bond to get out of jail. Once done, you would be required to appear before the court and tell why you failed to appear for court as a witness.

I suggest you appear on the date, time and place scheduled to give testimony.