The development of pyoderma gangrenosum (PG) after surgical site trauma is a rare, poorly understood immunologic phenomenon. PG is an immunologic disorder characterized by lymphocytic infiltration of the dermis that can manifest with skin necrosis and ulceration. This rare phenomenon can mimic surgical site infection (SSI) when it occurs in the perioperative period and in the region of surgical wounds. Within the neurosurgical literature, only two cases of postoperative PG have been reported to our knowledge. We describe the clinical features and treatment of PG in the case of a 65-year-old man who underwent a three-stage surgical approach for intractable mechanical low back pain on hospital days (HDs) 1 and 2, and who subsequently developed PG around all three surgical sites in the immediate postoperative period (HD 8). The physical and laboratory findings and surgical and pharmacologic treatments are detailed. The patient was initially treated for presumed SSI, started on broad-spectrum antibiotics, and underwent surgical wound debridement twice, without resolution of symptoms. The diagnosis of PG was ultimately made by a consulting dermatologist on HD 17. The patient was started on systemic immunosuppression with steroids during his initial hospitalization; symptoms resolved within two weeks of the index surgery. Although PG is a rare entity, we suggest that it be considered in the differential diagnosis of nonhealing surgical wounds. Familiarity with PG may help mitigate unnecessary surgical morbidity and reduce the length of hospital stays and unnecessary use of antibiotics.