Pre-clinical studies developing novel therapies to prevent cancer recurrence require appropriate surgical models. Here, we present a protocol for surgical debulking of subcutaneous tumors in mice, which allows for intraoperative application of immunotherapy-loaded biomaterials. We describe steps for inoculating tumor cells, anesthetizing mice, and performing surgery. We then detail procedures for applying biomaterial, bandaging mice, and data collection and analysis. The optimized bandaging regimen resolves the issue of wound dehiscence after surgery, for C57BL/6 mice, which interfere with surgical sites. For complete details on the use and execution of this protocol, please refer to Rwandamuriye et al.1 Display omitted •Steps for intraoperative application of therapy-loaded biomaterials during surgery•Instructions for bandaging to prevent post-operative wound interference•Guidance on assessing therapeutic efficacy and disease recurrence post-surgery Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics. Pre-clinical studies developing novel therapies to prevent cancer recurrence require appropriate surgical models. Here, we present a protocol for surgical debulking of subcutaneous tumors in mice, which allows for intraoperative application of immunotherapy-loaded biomaterials. We describe steps for inoculating tumor cells, anesthetizing mice, and performing surgery. We then detail procedures for applying biomaterial, bandaging mice, and data collection and analysis. The optimized bandaging regimen resolves the issue of wound dehiscence after surgery, for C57BL/6 mice, which interfere with surgical sites.