AbstractPyoderma gangrenosum (PG) belongs to the group of classical neutrophilic dermatoses and is characterised by painful ulcerations. While the clinical features have been well described, the underlying pathological mechanisms are incompletely understood and adequate treatment remains challenging. A 63‐year‐old male patient had suffered from recalcitrant ulcerations on the back, groins and legs for over 20 years. Due to suspicion of PG, a skin biopsy of the flank was obtained, which was confirming the suspected diagnosis. Following several frustrating attempts to treat, another skin biopsy was carried out and a cytokine profile by quantitative reverse transcription polymerase chain reaction was performed. Compared to healthy skin, a notable upregulation of interleukin (IL)‐17A and IL‐8 was detected. Subsequently, treatment with the anti‐IL17 antibody secukinumab was started. After 3 months of treatment, the PG area was 0 cm2. Due to the discontinuation of the drug by the patient typical PG lesions reappeared, all of which disappeared again within a few weeks of restarting secukinumab therapy. At month 23, the PG area was again 0 cm2 and this complete response was maintained under secukinumab therapy to this day (76 months after the onset of secukinumab therapy). This case of a patient with therapy‐resistant PG and subsequent long‐term responsiveness to anti‐IL‐17 therapy supports the potential importance of the Th17 axis in PG. Collectively, treatment of PG using IL‐17 antagonists seems to be very promising.