Police in Nam Tu Liem District said on Tuesday that in all four cases, he drove a motorbike and snatched the handbags from the women as they were walking on the street.
In one robbery on May 5 on Do Dinh Thien Street, a South Korean woman lost VND17 million ($730) and two mobile phones in her bag.
In April, he snatched the bags from two other South Korean women at a high-end apartment building. One of them lost VND5 million in cash and a smart phone while another lost her personal papers and bank cards.
The women have been advised to approach police in the district for any support they need.
If found guilty, Thao faces up to life imprisonment.