Unassociated Document For Release

Third Quarter Results

Washington - IsoRay Inc. (AMEX: ISR) a medical isotope company focusing on

treatment of prostate and other malignant disease through use of its proprietary

radioisotope technology, announced its financial results for the quarter

nine months ended March 31, 2008.

revenue for the quarter increased by 8 percent to approximately $1.8 million

over approximately $1.65 million in the year-earlier period. Medical centers

ordering the Company's Proxcelan seeds increased to 57, a 63 percent increase

over the 36 centers that ordered in the third quarter of fiscal 2007.

Company's revenues during the quarter were generated through sales of Proxcelan

Cesium-131 seeds for the treatment of prostate cancer. Since the first patient

implant in October 2004 through April 2008, approximately 2600 prostate cancer

patients have been treated with Cesium-131.

Company's net loss increased from approximately $2.0 million or $0.12 loss per

share in fiscal year 2007's third quarter, to approximately $2.2 million or

$0.09 loss per share in the quarter ended March 31, 2008. The increased loss

mainly due to depreciation costs of the new facility, increases in the cost

isotope, increased occupancy costs of the new facility and a small increase

sales and marketing.

Company had cash of approximately $3.4 million and short-term investments

approximately $6.5 million as of March 31, 2008.

Company had a gross margin of $100,661 for the three month period ended March

is to focus on increasing sales and decreasing operational costs by gaining

efficiencies in our core business, prostate brachytherapy" said IsoRay Chairman

and Interim CEO Dwight Babcock. "We continue to build on the past success of our

Cesium educational workshops, have refocused the sales force through a new

compensation package that increases the emphasis not only on generating new

customers but also supporting the growth of existing customers.

operations we are reviewing our production processes and initiating strategic

automation to reduce our labor costs and gain efficiencies."

added, "We are very pleased with the strong showing of additional clinical data

from the ongoing trials as well as the presentation of recommendations for

implanting brachytherapy with Cesium-131 by the Cesium Advisory Group at

American Brachytherapy Society meeting this past weekend in Boston."

fully subscribed Cesium educational workshop will be held on

29th and 30th, 2008 at the Chicago Prostate Cancer Center. Additional training

is planned to be available online through webcasts for physicians using real

time planning and techniques presented by Steve Kurtzman, M.D., IsoRay's Medical

Director, later this year.

pipeline during Q3-FY2008 included 7 new sites or customers that collectively

placed 11 orders for Proxcelan Cesium-131 brachytherapy seeds during the

sites received amended Radioactive Material (RAM) licenses; 15 sites have

submitted RAM licenses for amendment and 19 potential new sites have begun

process for amending their licenses during the quarter ended March 31, 2008.

previously announced, a conference call is scheduled for 1:30 p.m. Pacific

(4:30 p.m. Eastern Time) today to discuss this earnings release. Participants

should dial into the call 10-15 minutes before the scheduled time using the

following numbers: 877-407-9210 (from the US and Canada) or +1 201-689-8049

(from outside the US and Canada). A live webcast of the conference call will

also be accessible via the Internet at www.isoray.com,

going to www.investorcalendar.com.

telephonic replay of the conference call will be available by dialing

877-660-6853 (from the US and Canada) or +1 201-612-7415 (from outside the

and Canada) and by entering account number 286 and conference ID number

00284225. An online archive will also be available immediately following

call at the sites noted above. Both are available for ten days, through May

financial results reported today do not take into account any adjustments

may be required in connection with the completion of the Company's review

process and should be considered preliminary until IsoRay files its Form

for the fiscal quarter ended March 31, 2008.

Inc., through its subsidiary, IsoRay Medical, Inc., is the sole producer

Cesium-131 brachytherapy seed, used to treat prostate and other cancers.

Cesium-131 seed offers a significantly shorter half-life than the two other

isotopes commonly used for brachytherapy, which results in a substantially

faster delivery of therapeutic radiation, lower probability of cancer cell

survival and reduction of the longevity of common brachytherapy side

is based in Richland, Washington. More information is available about IsoRay

CI, Dale RG, Coles IP, et al. The Determination of Radiobiologically Optimized

Half-lives for Radionuclides Used in Permanent Brachytherapy Implants. Int.

Radiation Oncology Biol. Phys. 2003; 55 (2): 378-385.

B.R., Bice W.S., Jurkovic I., et al. Cesium-131 Permanent Prostate

Brachytherapy: An Initial Report. Int. J. Radiation Oncology Biol. Phys.

in this news release about IsoRay's future expectations, including: the

advantages of our Cesium-131 seed, future demand for IsoRay's existing and

planned products, IsoRay's manufacturing needs and capabilities, whether

sites will achieve licensure and result in future sales, whether planned

physician education activities will be held or will result in favorable

physician responses, whether changes in IsoRay's sales and marketing strategy

will result in improved sales, whether IsoRay will be able to reduce operating

costs and increase revenue, and all other statements in this release, other

historical facts, are "forward-looking statements" within the meaning of

Private Securities Litigation Reform Act of 1995 ("PSLRA"). This statement

included for the express purpose of availing IsoRay, Inc. of the protections

the safe harbor provisions of the PSLRA. It is important to note that actual

results and ultimate corporate actions could differ materially from those

such forward-looking statements based on such factors as physician acceptance,

training and use of IsoRay's products, changing levels of demand for IsoRay's

current and proposed future products; whether later studies and protocols

support the findings of the initial studies, success of future research and

development activities, IsoRay's ability to successfully manufacture, market

sell its products, IsoRay's ability to manufacture its products in sufficient

quantities to meet demand within required delivery time periods while meeting

its quality control standards, IsoRay's ability to enforce its intellectual

property rights, changes in reimbursement rates, changes in laws and regulations

applicable to our product, and other risks detailed from time to time in

IsoRay's reports filed with the SEC.