Price was jailed for her part in the IRA London bombing campaign of 1973. She was part of a unit that placed four car bombs in London on 8 March 1973. The 1973 Old Bailey bombing and that of the Whitehall army recruitment centre saw 200 injured. A warning was issued an hour before the blast. One man died of a heart attack, although an autopsy found his heart attack had begun before the Old Bailey blast. She and her sister Dolours Price were apprehended along with Hugh Feeney, Gerry Kelly, and six others, as they were boarding a flight to Ireland. They were tried and convicted at the Great Hall in Winchester Castle on 14 November after two days of deliberation by the jury. Marian Price was sentenced to two life terms.