The index closed 5.30 points lower after gaining 2.54 points in the previous session.
Trading on the Ho Chi Minh Stock Exchange increased by 9% to VND18.301 trillion (US$736 million).
The VN-30 basket, comprising the 30 largest capped stocks, saw 21 tickers fell.
MSN of conglomerate Masan Group saw the biggest drop of 2.2%, followed by BCM of Becamex Investment and Industrial Development with a 2.1% decline and VNM of dairy giant Vinamilk, down 2.0%.
Six blue chips gained. VHM of property giant Vinhomes went up 1.9%, VRE of retail real estate arm Vincom Retail rose 1.8%, and VIC of private conglomerate Vingroup closed 1.4% higher.
Foreign investors were net seller to the tune of VND389 billion, mainly selling VHM of Vinhomes and HPG of steelmaker Hoa Phat Group.
The HNX-Index for stocks on the Hanoi Stock Exchange, home to mid and small caps, fell 0.46%, while the UPCoM-Index for the Unlisted Public Companies Market went down 0.29%.
Globally, European shares were flat on Monday ahead of a raft of key economic data set to unfold through the week, while the technology sector kept gains in check, Reuters reported.
The pan-European STOXX 600 index was flat at 518.22. On Friday, the benchmark touched a more than three-week high and logged a third straight weekly gain.
London markets are closed for a holiday.