Purpose: The use of tissue expander/implant in breast reconstruction using tissue expander-implant is one of the most common surgical procedures. The use of AlloDerm as a sling to reestablish the lower pole of the pectoralis major muscle results a decrease in morbidity compared with more invasive procedures. However the use of AlloDerm is more expensive than other options. We decided to compare AlloDerm with Permacol, which has been safely used in human body reconstruction and is less costly than AlloDerm. Methods: After mastectomy, the inferolateral origin of the pectoralis major muscle was elevated. Either AlloDerm or Permacol was sutured to the chest wall at the level of the previously marked inframammary fold. The lower border of the pectoralis major muscle and the upper portion of the crescent-shaped piece of either AlloDerm or Permacol was sutured together using a tension free technique, and a tissue expander was subsequently inserted into the subpectoral-subAlloDerm (or Permacol) dual pocket. Results: AlloDerm was used in twenty-one patients (28 breasts) and Permacol was used in six patients (11 breasts) for tissue expander-implant breast reconstruction. During the mean follow-up period of 17 months (8~25 months). Two infections (7%) occurred in AlloDerm cases and four infections (36%) occurred in Permacol cases. Conclusion: This study is the first comparison of tissue expander/implant breast reconstruction using AlloDerm and Permacol. The use of Permacol resulted in more postoperative infection compared with the use of AlloDerm. This report is still limited with the small number of cases studied.