The fire started at around 10:20 a.m. on the first floor of the 70-story Keangnam tower in Tu Liem District.
City firefighters extinguished the flames just a few minutes later.
Choi Jae Ok, Keangnam's Administrative Officer, said that the building is still under construction and doesn't yet have a fire alarm system.
Some construction workers told Thanh Nien they did not know how to use the fire extinguishers available at the site.
The authorities are investigating the fire and assessing the damage.
South Korea’s Keangnam Enterprises Ltd. began work on the project in 2007.
When completed, the building will become Vietnam’s tallest skycraper, surpassing the current title-holder 68-story Bitexco Financial Tower in Ho Chi Minh City.
Despite its impressive height, the Keangnam project has become notorious for its poor safety record.
In March, Hanoi authorities launched an investigation into the construction site following the death of six workers – two in February and four in July 2009.
In March, a fire broke out on the 25th floor of the project.
Last month, a piece of debris fell from the site severely injuring a woman who was passing below.
