Periodontal diseases affect a large portion of the global population, imposing significant health and economic burdens. Traditional treatments, including antibiotics, face challenges like antibiotic resistance and rapid clearance from target sites. The study addresses these issues using nanoscale antimicrobial bismuth nanoparticles (BiNPs) delivered through electrospun gelatin methacryloyl (GelMA) nanofibrous mats. BiNPs were synthesized via a rapid chemical reduction process, yielding particles with an average size of 30 nm and a stable surface charge of −18 mV. These nanoparticles were incorporated into GelMA fibers through electrospinning and characterized using techniques such as scanning electron microscopy and Fourier transform infrared spectroscopy. The GelMA fibers exhibited a uniform morphology with a diameter of 414 nm, controlled degradation, and sustained BiNPs release. Adhesion to soft tissue was measured at ∼3 N, and the fibers maintained their mechanical strength after BiNPs incorporation. The BiNPs-loaded mats demonstrated potent antimicrobial activity, killing 100 % of Porphyromonas gingivalis, a key periodontal pathogen. Biocompatibility tests with periodontal ligament stem cells confirmed no significant cytotoxicity. This study highlights BiNPs-infused GelMA nanofibrous mats as a promising localized treatment for periodontal diseases, offering sustained antimicrobial activity, and biocompatibility.