Saudi Arabia has been battling increased rebel activity since May when triple bombings killed 35 people, including nine Americans, in Riyadh. Officials have blamed al-Qaida for both the May and November attacks.
The videotape aired by Dubai-based Al Arabiya showed fighters training and making explosives against a background of religious chants often heard in promotional videos of the al-Qaida network.
Al Arabiya said the 90-minute tape, which described the men as Saudi nationals, had been released on an al-Qaida website. The site was not accessible from Dubai.
The excerpts showed the faces of the two bombers who allegedly carried out the November attack, while others were masked.
Saudi Arabia said in December it had arrested a suspect in the bombing and seized a large cache of weapons.
Al-Qaida, led by the Saudi-born Usama bin Ladin, is seen as the mastermind behind the 11 September 2001 attacks on the United States.
Analysts say that over the last year al-Qaida and those linked to it have launched a campaign to overthrow the royals in Saudi Arabia, the world's largest oil exporter and home to Islam's holiest sites.