EXHIBIT 21 Subsidiaries of the Registrant The following are subsidiaries of the Registrant as of December 31, 2002 and the jurisdiction in which each is organized. Each of the subsidiaries conducts its business using the names indicated except as separately set forth herein. Certain subsidiaries are not listed. These omitted subsidiaries either individually or in the aggregate would not constitute a significant subsidiary. State or Country of Subsidiary Organization - ----------- ------------ Subsidiary of the Registrant: CDI Corporation (a) Pennsylvania Subsidiaries of CDI Corporation: CDI AndersElite Limited (b) United Kingdom CDI Engineering Group, Inc. (c) Delaware CDI Holdings (UK) Limited United Kingdom CDI Marine Company (d) Florida C.D.I. Professional Services Group, S. de R.L. de C.V. (e) Mexico CDI Technical Services, Ltd. (f) Canada Liquid Medium, LLC Delaware The M&T Company Pennsylvania Management Recruiters International, Inc. (g) Delaware Maplehill Corporation Delaware M.E. -Michigan, Inc Michigan Shares Services of West Virginia, Inc. Delaware Todays Staffing, Inc. (h) Pennsylvania Subsidiary of CDI AndersElite Limited: CDI AndersElite Ireland Limited Ireland EuroElite Plc United Kingdom Subsidiaries of CDI Engineering Solutions, Inc.: Herzog-Hart Limited United Kingdom Subsidiary of CDI Holdings (UK) Limited: Harvard Associates Limited United Kingdom Subsidiaries of Management Recruiters International, Inc.: Brownshill Corporation Delaware InterExec, Inc. (i) Ohio Management Recruiters of Cuernevaca, Inc. Ohio Subsidiary of Brownshill Corporation: Brownshill Holdings Limited United Kingdom State or Country of Subsidiary Organization - ----------- ------------ Subsidiary of Brownshill Holdings Limited: MRI Worldwide Ltd United Kingdom Subsidiary of Maplehill Corporation: Asset Computer Personnel Corporation Nova Scotia Subsidiaries of Todays Staffing, Inc.: Todays Staffing, Ltd. Canada Spectra Professional Search of Massachusetts, Inc. Massachusetts (a) CDI Corporation also conducts its business using the trade names of CDI Professional Services, CDI Innovantage, CDI Engineering Services, CDI Engineering Solutions and CDI Managed CADD Services. (b) CDI AndersElite Limited also conducts its business using the trade name of CDI Professional Services. (c) CDI Engineering Group, Inc. also conducts its business using the name of CDI Engineering Solutions. (d) CDI Marine also conducts its business using the name of CDI Government Services. (e) C.D.I. Professional Services Group, S. de R.L. de C.V. also conducts its business using the trade name of CDI. (f) CDI Technical Services Ltd. also conducts its business using the trade name of CDI Professional Services. (g) Management Recruiters International, Inc. also conducts its business using the trade names of Sales Consultants, Office Mates 5, CompuSearch, ConferView and Banister International. (h) Todays Staffing, Inc. also conducts its business using the trade names Todays Legal Staffing and Todays Office Staffing. (i) InterExec, Inc. also conducts its business using the trade name of DayStar.