Secondary intention healing offers an alternative when surgical options are infeasible. This study analyzed the effect of micronized acellular dermal matrices (mADMs; CGderm Matrix®, CG Bio, Seoul, Republic of Korea) on secondary intention healing in patients with complex soft-tissue defects and assessed mADMs’ efficacy in promoting secondary healing and improving clinical outcomes in these challenging cases. This retrospective study included 26 patients treated with sheet-type reprocessed mADMs between August 2022 and December 2022 at Soonchunhyang University Cheonan Hospital. Patients with full-thickness skin defects classified as complex wounds were included. Data on demographics, wound characteristics, and treatment outcomes were collected and analyzed. Wound area was measured using ImageJ software, and statistical analyses were conducted using SPSS. The application of mADMs resulted in a median wound area reduction of 81.35%, demonstrating its significant efficacy in wound healing. Most patients presented with compromised vascular supply, significant tissue loss, or infections that precluded conventional surgical interventions. No significant correlations were observed between patient variables and wound-healing outcomes, indicating the complex nature of wound healing. mADMs effectively promote secondary intention healing by providing a supportive extracellular matrix scaffold that enhances epithelialization and angiogenesis. Their rapid absorption, ease of handling, and ability to improve wound tensile strength make them particularly suitable for complex wounds.