EXHIBIT 21 LIST OF SUBSIDIARIES Principal subsidiary/undertaking Jurisdiction of incorporation Roberts Pharmaceutical Corporation State of New Jersey, USA Shire Pharmaceuticals Limited England and Wales Shire Pharmaceutical Development Limited England and Wales Shire International Licensing BV Netherlands Shire Laboratories Inc. State of Delaware, USA Shire Supplies US, LLC State of Delaware, USA Shire France S.A. France Shire Deutschland GmbH & Co. KG Germany Shire US Inc. State of New Jersey, USA Shire Pharmaceuticals Ireland Limited Ireland Shire Italia SpA Italy Shire Pharmaceutical Iberica S.L. Spain Shire Pharmaceutical Development Inc. State of Maryland, USA Shire BioChem Inc. Canada Shire Finance Limited Cayman Islands Shire Biologics Inc. State of Massachusetts, USA Shire Pharmaceutical Contracts Limited England and Wales Shire US Manufacturing Inc. State of Maryland, USA All of the Group's subsidiary undertakings are beneficially owned (directly or indirectly) as to 100% and are all consolidated in the results of the Group.