The defence announced on Tuesday that Murray will not be taking the stand.
Murray told a judge about his decision during a court session without the presence of jurors. After being asked whether he understood that the choice to testify or not was solely his, Murray said: "My decision is I will not testify in this matter."
He had previously told Los Angeles Superior Court Judge Michael Pastor that he had not yet made up his mind on the issue.
Last week, the defence argued that Michael Jackson could have administered a fatal injection of propofol himself.
The prosecution had previously suggested that Jackson died after Murray administered him an IV drip infused with propofol.
On Monday, it was reported that defence witness Dr Paul White is facing a possible contempt of court charge and a $1,000 (£622) fine.
The trial continues.