The 30-share barometer, which gained 342 points in the last three sessions, moved down by 43.29 points, or 0.22 per cent, to 19,721.49, with stocks of realty, metals and banking sectors leading the fall.
Similarly, the wide-based National Stock Exchange index Nifty, dipped below the 6,000-mark by losing 14.45 points, or 0.24 per cent, to 5,995.05.
Brokers said besides profit-booking by speculators, a mixed trend at the Asian markets following overnight losses at on the US markets, influenced the sentiments.
In Asia, Japan stock market which resumed trading after long winter-break, was trading 2.61 per cent higher, while Hong Kong's Hang Seng index shed 0.12 per cent in early trade today.
In the US market, Dow Jones Industrial Average ended 0.16 per cent lower in yesterday's trade.