EXHIBIT 21 LIST OF SUBSIDIARIES OF MENTOR GRAPHICS CORPORATION Jurisdiction of Name Organization Mentor Graphics (UK) Limited England Mentor Graphics (France) SARL France Mentor Graphics Italia SpA Italy Mentor Graphics (Deutschland) GmbH West Germany Mentor Graphics (Denmark) Denmark Mentor Graphics (Netherlands) B.V. Netherlands Mentor Graphics Finance B.V. Netherlands Mentor Graphics (Singapore) Pte., Ltd. Singapore Mentor Graphics Japan Co., Ltd. Japan Mentor Graphics (Scandinavia) AB Sweden Mentor Graphics (Finland) AB Finland Mentor Graphics (Canada) Ltd. Canada Mentor Graphics (Schweiz) AG Switzerland European Development Center Belgium