Clean Diesel Technologies, Inc. Effective Registration Statement.

STAMFORD, Conn. -- Clean Diesel Technologies, Inc. (NASD: CDTI; AIM: CDT/CDTS; XETRA: CDI), provider of innovative technologies and solutions that reduce emissions, conserve fuel and improve engine performance, announced today that its Registration Statement on Form S-1 covering the resale by holders of up to 2.8 million shares of common stock, $0.01 par value, was declared effective at 5:00 p.m. EST on October 4, 2007 by the Securities and Exchange Commission. The registered securities comprise those issued by the Company in connection with its December 2006 private placement (primarily under Regulation S), including 690,500 common shares that are not presently outstanding but that may be issued upon the exercise of the Company's Class B warrants. A prospectus may be obtained by a request to the Company at the address below or by visiting the SEC's website (http://www.sec.gov). This press release does not constitute an offer to sell or the solicitation of an offer to buy securities in any jurisdiction.

About Clean Diesel Technologies

Clean Diesel Technologies, Inc., together with its wholly-owned subsidiary, Clean Diesel International, LLC, is a clean energy and environmental technology company that provides innovative solutions to reduce harmful engine emissions and conserve energy. Clean Diesel Technologies' patented technologies, products and solutions enable cost-effective reduction of harmful emissions from internal combustion engines while also improving fuel economy and power. Products include Platinum Plus([R]) fuel-borne catalysts, the Platinum Plus Purifier[TM] Systems, the ARIS([R]) urea injection systems for selective catalytic reduction of NOx, diesel particulate filter and biofuels technologies. Their products are in commercial use around the world. Platinum Plus and ARIS are registered trademarks of Clean Diesel Technologies, Inc. For more information, visit Clean Diesel at www.cdti.com or contact the Company directly.

Certain statements in this news release constitute "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Such forward-looking statements involve known or unknown risks, including those detailed in the Company's filings with the US Securities and Exchange Commission, uncertainties and other factors which may cause the actual results, performance or achievements of the Company, or industry results, to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof.