The scrip, which carries the maximum weight on the BSE 30-share Sensex, opened the day on a poor note and fell further by 12.61 per cent to close the week's trade at Rs 2,403.30 on BSE.
On the National Stock Exchange Nifty, the stock shed 12.66 per cent at the same time to Rs 2,402.55.
Infosys has 9.23 per cent weight in the 30-share Sensex pack, followed by RIL, which has 9.21 per cent weight.
In its biggest fall in nearly three years, Infosys wiped out nearly Rs 20,000 crore in market value, as disgruntled investors resorted to hectic selling.
Analysts said the biggest disappointment was the revenue guidance for the next year, which is taken as a benchmark for the IT industry as a whole.
"The year ahead looks challenging for the IT services industry, with slow recovery in global markets," Infosys chief executive S.D. Shibulal said in a statement after the company declared financial results for the fourth quarter (Q4) under review.
Other leading IT stocks also came under pressure, with TCS trading lower by 5.47 per cent and Wipro was down 4.10 per cent.
Led by massive sell-off in leading stocks, the BSE IT index lost 8.76 per cent to close the day at 5,402.47 and was the biggest loser among the 13 sectoral indices.
The company reported Rs 2,316 crore net profit for the fourth quarter of 2011-12, registering 27.4 per cent YoY growth, but 2.4 per cent lower sequentially from the third quarter of 2011-12 (Rs 2,372 crore).
On the hiring front, though, the company and its subsidiaries added 10,676 people, during the fourth quarter of 2011-12, net addition was 4,906 as 5,770 quit in three months, taking the total number of employees for the fiscal under review (2011-12) to 149,994 from 145,088 a quarter ago and 130,820 a year ago.