EXHIBIT 21

SUBSIDIARIES OF THE REGISTRANT

The following is a list of subsidiaries of the Registrant:

Registrant and Parent:

Rowan Companies, Inc.

Wholly-Owned Subsidiaries of Registrant:

Rowan International, Inc., a Panamanian corporation
Rowan Drilling Company, Inc., a Texas corporation
Atlantic Maritime Services, Inc., a Texas corporation
LeTourneau, Technologies, Inc., a Texas corporation
RDC Arabia Drilling, Inc., a Texas corporation
Rowan Marine Drilling, Inc., a Panamanian corporation
LeTourneau Technologies Drilling Systems, Inc., a Texas corporation

Note: Certain subsidiaries have been omitted from this listing because such subsidiaries, when considered in the aggregate as a single subsidiary, would not constitute a significant subsidiary.