The 30-share barometer fell by 18.32 points, or 0.09 per cent, to 19,965.46 with stocks of banking, IT and metal succumbing to profit-booking. It had crossed the 20,000-mark after two years in yesterday's trade.
The index had gained nearly 324 points in the last two sessions.
Similarly, the wide-based National Stock Exchange index Nifty, moved down by 12.80 points, or 0.21 per cent, to 6,043.80.
Brokers said besides profit-booking by speculators after recent gains, a weak trend at the Asian markets influenced the sentiments.
In the Asian region, Hong Kong's Hang Seng fell by 0.50 per cent, while Japan's Nikkei declined by 1.52 per cent in early trade today.
In the US market, Dow Jones Industrial Average ended 0.20 per cent higher in yesterday's trade.
