Abstract A 32-year-old woman who was breastfeeding presented 7 weeks postpartum with right breast pain, swelling and erythema. A clinical diagnosis of mastitis was confirmed on ultrasound, and she was started on intravenous (IV) flucloxacillin. Initial cultures grew methicillin-sensitive Staphylococcus aureus, and clindamycin was added. She failed to improve and 6 days later an abscess was incised and drained. A vacuum-assisted closure (VAC) dressing was placed over the wound postoperatively. Over the following 3 days, she deteriorated clinically with markedly increased pain, spiking temperatures and malaise. Linezolid and metronidazole were added. On return to theatre for wound review, she had an 18 cm × 10 cm deep necrotic ulcer with purulent discharge, sparing the nipple. The breast surgeon’s concern was that of necrotizing fasciitis, and an immediate wider debridement was performed, removing all breast skin except for the nipple. Dermatology was then consulted, and a diagnosis of pyoderma gangrenosum (PG) was made. The patient was commenced on IV methylprednisolone 1 g daily for 3 days. Her temperature normalized immediately, and her C-reactive protein dropped from 141 to 27 mg L−1 in 24 h. The previously rolled, violaceous wound edges settled with no further progression. Following 3 days of steroid, ciclosporin 5 mg kg−1 daily was commenced. The right breast continued to lactate, and the very large defect now present was anticipated to pose many difficulties for the young mother. Five weeks after the initial presentation, and following multidisciplinary discussion, a biodegradable temporizing matrix (BTM; NovoSorb®) was applied, under continued dermatologist-supervised immunosuppression. The BTM took with good effect. Two weeks later, a split-thickness skin graft was applied to the BTM. The skin grafting took successfully, with no reactivation of PG postoperatively. Three months postgrafting, the patient is now being weaned off ciclosporin and remains well. Postpartum PG is rare and is predominantly reported at the site of caesarean section incision. Surgery is typically discouraged in PG owing to the risk of disease reactivation. However, surgery in this case was considered appropriate due to the rapid disease control with immunosuppression, the extent of ulceration, the expected prolonged healing period requiring exposure to the toxicity of ciclosporin and the avoidance of cribriform scarring often seen with PG. This case highlights how PG should always be considered in postpartum patients presenting with rapidly progressing, nonhealing ulcers. It also shows that, despite our usual treatment practices, in certain cases, early surgical intervention can be considered alongside ongoing immunosuppression resulting in positive patient outcomes.