The index closed 0.83 points lower after gaining 14.64 points on Monday.
Trading on the Ho Chi Minh Stock Exchange (HoSE) fell by 4.17 percent to VND13.58 trillion ($578.24 million).
The VN-30 basket, comprising the 30 largest capped stocks, saw 16 tickers dropped.
VHM of property giant Vinhomes fell 3%, followed by VIC of private conglomerate Vingroup with a 2.1% drop.
BCM of Becamex Investment and Industrial Development lost 1.8% and SAB of brewer Sabeco dropped 1.7%.
Thirteen blue chips gained, with POW of electricity producer Petrovietnam Power Corporation and SSI of leading brokerage SSI Securities Corporation recording 2.3% rise.
Foreign investors were net sellers to the tune of VND270.25 billion, mainly selling STB of Ho Chi Minh City-based lender Sacombank and VNM of dairy giant Vinamilk.
The HNX-Index at the Hanoi Stock Exchange, where mid and small caps list, was up 0.12% while the UPCoM-Index at the Unlisted Public Companies Market was up by 0.40%.