A political action committee formed by Giffords and husband Mark Kelly says it began airing a TV commercial Monday that shows images of the aftermath of four mass shootings and an on-camera appeal by Giffords for congressional action.
She's recovering from a head wound suffered in a January 2011 shooting in Tucson.
The ad specifically calls for universal background checks of gun purchasers.
Americans for Responsible Solutions says the ad is airing in Washington and in home districts and states of congressional leaders in San Francisco, Cincinnati, Las Vegas and Louisville, Ky.
Group spokeswoman Jen Bluestein will only say the cost of the airtime tops $100,000.