Exhibit 23(a)

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM


We  consent  to  the incorporation by reference in the registration statement on
Form  S-8  (Registration Nos. 333-16939, 333-33276 and 333-117057) of our report
dated  February  15,  2006, except note 4 as to which the date is March 3, 2006,
relating  to  our  audit of the financial statements for the year ended December
31,  2005  of Clean Diesel Technologies, Inc. included in the 2005 annual report
on  Form  10-K.




/s/  Eisner  LLP
New  York,  New  York
March  24,  2006