BACKGROUND Fournier's gangrene (FG) is a rapidly progressive necrotizing infection of the perineum. Risk factors include male sex and immunosuppression. Inflammatory bowel disease and pregnancy may alter immune response by complex mechanisms but have rarely been associated with necrotizing infections of the perineum. To the best of our knowledge, only 5 cases of FG in association with IBD have been reported in the literature, and none of them occurred during pregnancy. CASE REPORT We report the case of a young woman with long-standing Crohn's disease in clinical remission with Infliximab monotherapy who developed FG in the third trimester of pregnancy. A cesarean section was undertaken at 35 weeks due to fetal distress, followed by debridement, diverting stoma, and vacuum-assisted therapy. The perineal defect was closed following 4 debridements and vacuum-therapy exchanges with a unilateral medial thigh advancement flap, and a draining seton was placed in the suprasphincteric fistula. The patient was discharged after 28 days and her recovery was unremarkable. The neonate also recovered well. CONCLUSIONS The treatment of FG is multidisciplinary and includes early debridement and intestinal diversion. Perianal pain should not be disregarded, as it may be the initial symptom of severe perianal sepsis in the immunosuppressed. To the best of our knowledge, this is the first case report of FG during pregnancy in a patient with Crohn's disease.