Exhibit 21 Subsidiaries of Atrion Corporation As of December 31, 2002 State of Subsidiary Incorporation Ownership - ----------------------------------------------------------------- Atrion Medical Products, Inc. Alabama 100% Halkey-Roberts Corporation Florida 100% Quest Medical, Inc. Texas 100% AlaTenn Pipeline Company LLC Alabama 100% Atrion Leasing Company LLC Alabama 100% Atrion International, Inc. U.S. V. I. 100% - ----------------------------------------------------------------- -53-