The 30-share index fell by 117.87 points, or 0.49 per cent, to 23,753.36 at midsession today.
The Sensex had touched an all-time intra-day high of 24,068.94 in yesterday's trade after exit polls predicted that BJP-led NDA will form the government at the Centre.
The gauge had soared over 1,527 points in the past three sessions.
The broad-based Nifty of the National Stock Exchange slipped from the psychological 7,100 level by losing 27.85 points, or 0.39 per cent, to 7,080.90. It climbed to an intra-day record high of 7,172.35 in the previous session.
Besides, a mixed trend at the other Asian bourses and a weak opening on the European markets, too weighed on the sentiments here, they said.
Major losers, which dragged the Sensex down were BHEL, Larsen and Toubro, Reliance Industries, Axis Bank, ICICI Bank, Infosys, Maruti Suzuki, Mahidnra and Mahindra and Dr Reddy Lab.