The 30-year-old groom, whose name has not been disclosed, had a fever but the coronavirus alarm proved to be unfounded.
On February 27 the man came with his parents and younger brother from Japan to the bride's house in Ha Long in the northern province of Quang Ninh for the wedding to be held on Sunday at a local restaurant.
They stayed at a four-star hotel.
On Sunday afternoon, after receiving news that the groom had fever, local authorities asked the bride's family to cancel the ceremony, fearing he might have Covid-19. The disease has spread to 76 countries and territories, with Japan being a hotspot.
The bride’s family agreed, and both families were taken to the isolation area at a local hospital for testing for Covid-19.
The couple and the groom’s three family members tested negative, and the Japanese visitors left Vietnam on Monday.
Thirty guests who had come to attend the wedding, mainly relatives of the bride, have been quarantined at home.
As of Monday Quang Ninh, which shares a border with China, has isolated 574 suspected cases.
Outside mainland China, besides Japan, South Korea, Iran and Italy are the worst affected. As of Tuesday Japanese authorities reported 275 cases including 12 deaths, with six from a cruise ship.
Vietnam has had 16 cases, but all have recovered.
The global death toll is 3,069, mostly in China.