Background: Psoriasis is a chronic in ammatory skin disease with many clinical presentations. The most common variety is chronic plaque psoriasis. Rare chronic plaque psoriasis subtypes include annular, licheni ed, and hyperkeratotic. Hyperkeratotic forms include ostraceous, rupioid, and elephantine. Some authors ignore the distinction between the types of hyperkeratotic psoriasis. Nevertheless, biological therapies have not been extensively researched in such rare cases of psoriasis. We present a case of intractable hyperkeratotic psoriasis that was successfully treated with guselkumab. Case presentation: According to the physical examination of our 45-year-old male patient, the abdomen had con uent plaques and thick sero-exudative crusts. Erythematous, crusted, limpet-like lesions covered the back. The scales passed the Grattage test. The biopsy showed psoriasis features. After two months of guselkumab therapy, lesions were PASI 100. After a year of 8-week guselkumab medication, the patient's reaction was unchanged. Accordingly, guselkumab was given every 10 weeks for six months. The patient was disease-free except for a few minor lesions on the back and abdomen that disappeared following topical steroid cream. Conclusions: Our patient had elephantine and rupioid psoriasis on the abdomen and back, respectively. This twofold presentation in the same patient supports the idea that hyperkeratotic psoriasis subtypes are interchangeable. The natural evolution of hyperkeratotic psoriasis lesions may explain this appearance, which has never been recorded. In this case report, guselkumab was highly e ective at treating severe hyperkeratotic psoriasis in a real-world clinical environment for 1.5 years.