Exhibit 21
SUBSIDIARIES OF REGISTRANT
Clean Diesel Technologies, Inc.'s subsidiaries as of December 31, 2013 are listed below.
| Name of Subsidiary |
| State/Jurisdiction of Incorporation |
| Common Equity Ownership |
|
|
|
|
|
|
| Clean Diesel Technologies Limited |
| United Kingdom |
| 100% |
| Catalytic Solutions, Inc. |
| California |
| 100% |
| CSI Aliso, Inc. |
| California |
| 100% |
| Catalytic Solutions Holdings, Inc. |
| Delaware |
| 100% |
| ECS Holdings, Inc. |
| Delaware |
| 100% |
| Engine Control Systems Ltd. |
| Nevada |
| 100% |
| Engine Control Systems Limited |
| New Brunswick |
| 100% |
| CDTI Sweden AB |
| Sweden |
| 100% |