The index closed 1.21 points higher after gaining 0.92 points on Monday.
Trading on the Ho Chi Minh Stock Exchange (HoSE) increased by 18.95% to VND9.58 trillion ($407.57 million).
The VN-30 basket, comprising the 30 largest capped stocks, saw 15 tickers gain.
PLX of fuel distributor Petrolimex and SSI of leading brokerage SSI Securities Corporation both led with a 1.9% rise.
They were followed by VNM of dairy giant Vinamilk, up 1.8% and POW of electricity producer Petrovietnam Power Corporation, up 1.1%.
Thirteen blue chips fell.
Three banks, ACB of Asia Commercial Bank, TCB of the largest private lender Techcombank and VPB of private lender VPBank, dropped 1%.
Foreign investors were net buyers to the tune of VND139.29 billion, mainly buying HPG of steelmaker Hoa Phat Group and VPB.
The HNX-Index at the Hanoi Stock Exchange, where mid and small caps list, was up 0.78% while the UPCoM-Index at the Unlisted Public Companies Market was up by 0.45%.