AlloDerm (LifeCell, Branchburg, NJ) is gaining acceptance in tissue expander/implant (TE/I) breast reconstruction. Anecdotal evidence suggests its use limits postoperative musculoskeletal morbidity and allows injection of greater initial fill-volumes and rapid postoperative expansion. The objective of this study was to evaluate AlloDerm's impact on expansion rates in immediate TE/I reconstruction. A matched, retrospective cohort study was performed. Medical records of patients who underwent immediate TE/I reconstruction from 2004 to 2005 were reviewed. Two cohorts were identified: (1) underwent TE/I reconstruction with AlloDerm, and (2) underwent standard TE/I reconstruction. Individuals were matched 1:1 on the basis of: expander size (+/-100 mL), history of irradiation, and indication for mastectomy. Cohorts were compared for intraoperative volume injected (mL), rate of postoperative expansion (mL/ injection), number of expansions, and time to completion of expansion (days). Incidence of complications was evaluated. Pairwise comparisons were performed using the Wilcoxon sign rank test and McNemar test. Ninety immediate TE/I reconstructions were evaluated. Forty-five TE/I-AlloDerm reconstructions were matched to standard TE/I reconstructions. Intraoperatively, expanders in the AlloDerm and non-AlloDerm cohorts were filled to a mean volume of 223.8 and 201.1 mL (P = 0.180). Median number of expansions performed was 5 and 6 in the AlloDerm and non-AlloDerm cohorts (P = 0.117). There was no difference in the mean rate of postoperative tissue expansion (AlloDerm: 97 mL/injection versus non-AlloDerm: 95 mL/injection [P = 0.907]), nor in the incidence of complications (P = 0.289). Minor complications occurred in 13.1% of AlloDerm cases (cellulitis [n = 3], seroma [n = 3], hematoma [n = 1]. Although this study does not address AlloDerm's efficacy in decreasing morbidity or improving esthetic outcomes in TE/I reconstruction, it indicates that AlloDerm does not increase the rate of tissue expansion after immediate TE placement. It does not, however, appear to increase the risk of postoperative complications.