La Sexta got the broadcast license on 25 November 2005. It began testing the broadcast on December 12, shortly before knowing the analog frequencies assigned to Madrid and Barcelona.On December 23, broadcasts started in Madrid and Barcelona, expanding later to all Spain.
Starting January 23, 2006 they began broadcasting a promotional video. February 20th marked the start of content emissions testing. Actual broadcasts started with documentaries (Champions, Natura) and programs dedicated to tuning, like 'Tuning Mania'. From the February 22nd, La Sexta broadcasted twelve hours of programming everyday.On March 2nd, a football match between Croatia and Argentina was the occasion for the first live broadcast. Five days before the actual date, José Miguel Contreras announced the official starting date, March 27, on the 'Círculo de Bellas Artes'.