EXHIBIT 21 PLC SYSTEMS INC. SUBSIDIARIES OF REGISTRANT 1.) PLC Medical Systems, Inc., a Delaware Corporation 2.) PLC Sistemas Medicos Internacionais Lda, a Madeira Corporation 3.) PLC Sistemas Medicos Internacionais GmbH, a German Corporation 4.) PLC Medical Systems France SARL, a French Corporation 5.) PLC Medical Systems AG, a Swiss Corporation 6.) PLC Medical Systems Asia/Pacific Pte Ltd, a Singapore Corporation 7.) PLC Medical Systems Australia Pty Ltd, an Australian Corporation