Objective. The aim of this study is to evaluate how treatment with total contact cast (TCC) affects the balance of proteases in diabetic foot ulcers (DFUs) as they heal. Materials and Methods. This was a prospective observational study of 22 eligible patients with neuropathic plantar DFUs in a hospital-based wound care center. All patients treated with TCC had adequate arterial circulation (ankle-brachial index > 0.75), no sign of infection, and all DFUs were grade 1A according to the University of Texas Diabetic Wound Classification System. Patients had weekly follow-up visits for wound evaluation and reapplication of the TCC. Wound tissues were obtained at baseline (week 0 prior to initial treatment), week 3, week 6, and week 12. Tissue homogenates were analyzed for matrix metalloprotease (MMP) 2, MMP-9, tissue inhibitor matrix metalloproteinase (TIMP) 1, and TIMP-2. Wound measurements were obtained at weekly follow-up visits, and healing rates were calculated by photodigital planimetry. Results. Treatment with TCC for 3 weeks resulted in a 20% decrease in MMP-2 (P = .031) and 44% decrease in MMP-9 (P = .018). By week 6, MMP-2 and MMP-9 levels were reduced by 37% and 55%, respectively. Tissue inhibitor matrix metalloproteinase 1 increased by 42% (P = .033) and TIMP-2 by 44% (P = .04) after 6 weeks of therapy with TCC. Conclusions. This significant and rapid drop of both MMP-2 and MMP-9 strongly suggests a decline of the inflammatory phase and initiation of the proliferation phase.