The index closed 4.28 points higher after dropping 2.07 points in the previous session.
Trading on the Ho Chi Minh Stock Exchange increased by 6% to VND12.751 trillion (US$500.9 million).
The VN-30 basket, comprising the 30 largest capped stocks, saw 18 tickers gained and 12 fell.
POW of electricity producer Petrovietnam Power Corporation rose 2.0%, HPG of steelmaker Hoa Phat Group went up 1.3%, and PLX of fuel distributor Petrolimex gained 1.0%.
VHM of property giant Vinhomes slid 1.0%, VJC of budget airline Vietjet dropped 0.9%, and VRE of retail real estate arm Vincom Retail closed 0.3% lower.
Foreign investors were net buyers to the tune of VND5 billion, mainly buying FPT of IT giant FPT Corporation and HPG.
The HNX-Index for stocks on the Hanoi Stock Exchange, home to mid and small caps, rose 0.24%, while the UPCoM-Index for the Unlisted Public Companies Market went up 0.32%.
Globally, European stocks were little changed on Wednesday as caution prevailed ahead of the Federal Reserve's policy decision and outlook, outweighing a rise in Renault on talks of a potential merger between carmakers Honda and Nissan, Reuters reported.
The pan-European STOXX 600 was trading flat.
French carmaker Renault rose 6%, lifting automakers by 0.8%. The company owns a 36% stake in Nissan.
The UK's FTSE 100 rose 0.2% as sterling came under pressure ahead of the Bank of England's rate decision on Thursday.