The 16-page newspaper is printed at the Financial Times presses in east London and has an office near by.
Its front-page editorial in the first issue said its political stance would be neutral. It contained no classified advertising, but plenty of display adverts.
It has four pages of news, three pages of listings and three pages of sport, horoscopes and a property column. Jim Basford, Tonight's circulation manager, said 100,000 copies a day would be printed and given to commuters at stations.
The paper was set up by a Leeds industrialist, Dereck Clee, and Geoff Steggals, a computer systems consultant.
Stewart Steven, editor of the Evening Standard, which sells more than 500,000 copies a day, said he did not expect it to affect his sales or advertising. The Standard took no action yesterday to meet the extra competition.