A recent Twitter post by Westlife front-man Mark Feehily says the Irish boy band will play in Hanoi on October 1.
The post has stirred up fans in Vietnam, where Westlife is one of the most popular foreign acts.
The tweet lists Vietnam as one of the destinations on the band's Asian tour to promote their 11th album, titled "Gravity."
Founded in 1998, the five-member band includes Nicky Byrne, Kian Egan, Mark Feehily, Shane Filan and Brian McFadden (who departed from the band in 2004).
In 2009, Brian came to Vietnam to perform at Hennessy Artistry (now H-Artistry,) an annual music event.
Increasingly large foreign acts have played Vietnam in recent years, including Ronan Keating, the Back Street Boys, and Bob Dylan.
Rumors are also circulating that Link'in Park and Bon Jovi will play Vietnam later this year.