OPNT Opiant Pharmaceuticals Inc

OPNET Technologies, Inc. (Nasdaq:OPNT) will hold an investor conference call on Tuesday, May 11, 2010 at 5:00 pm Eastern Time to review financial results for the fourth quarter of fiscal 2010.

To listen to the OPNET investor conference call:

Call 877-377-7550 in the U.S. or 408-337-0151 for international callers, or

Use the webcast at www.opnet.com. Investors are advised to go to the web site at least 15 minutes early to register, download, and install any necessary audio software.

To listen to the archived call:

Call the replay phone number at 800-642-1687 or 706-645-9291 for international callers. For replay, enter passcode

# 69117414. The replay will be available from 8:00 pm Eastern Time May 11th through 11:59 pm Eastern Time May 18th.

The webcast will be available at www.opnet.com, archived for seven days.

The fourth quarter of fiscal 2010 financial results will be released after the market closes on Tuesday, May 11, 2010.

About OPNET Technologies, Inc.

Founded in 1986, OPNET Technologies, Inc. (Nasdaq:OPNT) is a leading provider of solutions for managing networks and applications. For more information about OPNET and its products, please visit www.opnet.com.

OPNET and OPNET Technologies, Inc. are trademarks of OPNET Technologies, Inc. All other trademarks are the property of their respective owners.

CONTACT: OPNET Technologies, Inc.

OPNET Media Contact:

Margarita Castillo

(240) 497-3000

Media@opnet.com

OPNET Investor Relations:

Mel Wesley

(240) 497-3000

ir@opnet.com

www.opnet.com