IGI Western Asset Investment Grade Defined Opportunity Trust Inc

Western Asset Investment Grade Defined Opportunity Trust Inc., which is listed on the New York Stock Exchange under the symbol “IGI”, today announced the financial position of the Fund as of August 31, 2010.

  Current Q   Previous Q   Prior Yr Q† August 31, 2010 May 31, 2010 August 31, 2009 Total Net Assets $ 228,878,816 $ 217,587,723 $ 211,934,353 NAV Per Share of Common Stock (a) $ 21.53 $ 20.53 $ 20.10 Market Price Per Share $ 21.68 $ 20.90 $ 19.75 Premium / (Discount) 0.70% 1.80% (1.74)% Outstanding Shares 10,629,264 10,597,998 10,542,556   Total Net Investment Income (b) $ 3,093,402 $ 3,198,282 $ 1,550,071 Total Net Realized/Unrealized Gain/(Loss) (b) $ 10,879,343 $ (312,416) $ 10,534,270 Net Increase (Decrease) in Net Assets From Operations (b) $ 13,972,745 $ 2,885,866 $ 12,084,341  

Earnings per Common Share Outstanding

Total Net Investment Income (b) $ 0.29 $ 0.30 $ 0.15 Total Net Realized/Unrealized Gain/(Loss) (b) $ 1.02 $ (0.03) $ 1.00 Net Increase (Decrease) in Net Assets From Operations (b) $ 1.31 $ 0.27 $ 1.15   Undistributed/(Overdistributed) Net Investment Income (c) $ 787,510 $ 153,062 $ 450,194 Undistributed/(Overdistributed) Net Investment Income Per Share (c) $ 0.07 $ 0.01 $ 0.04 Footnotes: †     For the period June 26, 2009 (commencement of operations) to August 31, 2009. (a) NAVs are calculated as of the close of business on the last business day in the periods indicated above. (b) For the quarter indicated, unless otherwise noted. (c) As of the period indicated above.

This financial data is unaudited.

The Fund files its semi-annual and annual reports with the Securities and Exchange Commission, as well as its complete schedule of portfolio holdings for the first and third quarters of each fiscal year on Form N-Q. These reports are available on the Commission’s website at www.sec.gov. To obtain information on Form N-Q or a semi-annual or annual report from the Fund, shareholders can call 1-888-777-0102.

Western Asset Investment Grade Defined Opportunity Trust Inc., a non-diversified, closed-end management investment company, is managed by Legg Mason Partners Fund Advisor, LLC, a wholly-owned subsidiary of Legg Mason, Inc., and is sub-advised by Western Asset Management Company, an affiliate of the manager.

For more information, please call 1-888-777-0102 or consult the Fund’s web site at www.leggmason.com/cef.

Data and commentary provided in this press release are for informational purposes only. Legg Mason and its affiliates do not engage in selling shares of the Fund.