The index closed 23.45 points lower after gaining 12.14 points on Monday.
Trading on the Ho Chi Minh Stock Exchange (HoSE) increased by 26.65% to VND12.17 trillion ($515.35 million).
The VN-30 basket, comprising the 30 largest capped stocks, saw 24 tickers dropped.
PDR of Phat Dat Real Estate Development hit the floor with a 6.9% fall.
HPG of steelmaker Hoa Phat Group fell 6.6% and NVL of property developer Novaland Group lost 5.2%.
GVR of Vietnam Rubber Group went down 5.1% and SSI of leading brokerage SSI Securities Corporation declined by 4.7%.
Five blue chips bucked the trend.
TPB of private TPBank went up 1.2% and PLX of fuel distributor Petrolimex gained 0.5%.
Foreign investors were net buyers to the tune of VND37.26 billion, mainly buying STB of Ho Chi Minh City-based lender Sacombank and CTG of state-owned lender VietinBank.
The HNX-Index at the Hanoi Stock Exchange, where mid and small caps list, was down 2.08% while the UPCoM-Index at the Unlisted Public Companies Market was down by 0.55%.