The index closed 0.73 points higher after rising 1.77 points Monday.
Trading on the Ho Chi Minh Stock Exchange (HoSE), on which the index is based, fell 2% to VND21.71 trillion ($911.42 million).
The VN30 basket, comprising the 30 largest capped stocks, saw 15 tickers gained.
SSI of leading brokerage SSI Securities Corporation led with a 6.4% rise, followed by SSB of Southeast Asia Commercial Bank (SeABank), up 6%.
MWG of electronics retail chain Mobile World gained 2% and BVH of insurance company Bao Viet Holdings closed 1.8% higher.
Fourteen blue chips fell.
VIC of private conglomerate Vingroup dropped 2% and SAB of brewer Sabeco declined by 1.8%.
The HNX-Index for stocks on the Hanoi Stock Exchange, home to mid and small caps, gained 0.71% while the UPCoM-Index for the Unlisted Public Companies Market rise 0.01%.