INTRODUCTION: Pyodermatitis-pyostomatitis vegetans (PPV) is a rare inflammatory mucocutaneous dermatosis of unknown etiology. It is characterized by the appearance of vesicles, pustules, vegetating plaques, and erythematous lesions, often associated with underlying inflammatory bowel diseases such as Crohn's disease. OBJECTIVE: To report a case of vegetative pyostomatitis in a patient with Crohn's disease, focusing on the diagnostic process and therapeutic approach. CASE REPORT: A 47-year-old female patient, identified as AMSP, with a known diagnosis of Crohn's disease and a history of colostomy, presented with complaints of lesions affecting both the skin and oral mucosa. Dermatological examination revealed a well-defined, flat, round lesion with darkened borders in the right axillary region. Intraoral examination showed erythematous, net-like plaques along the lateral border of the tongue, accompanied by ulcerations and vesicles. An incisional biopsy of the tongue was performed. Histopathological analysis revealed a predominantly eosinophilic inflammatory infiltrate in the connective tissue and epithelial acantholysis. The clinical presentation, patient history, and histopathological findings led to the diagnosis of pyodermatitis-pyostomatitis vegetans. The patient was treated with topical 0.1% tacrolimus ointment applied twice daily for 15 days. Following this intervention, there was complete resolution of the lesions. CONCLUSION: Pyodermatitis-pyostomatitis vegetans is an uncommon condition that may serve as an oral and cutaneous manifestation of Crohn's disease. The presence of vegetating plaques on the skin and vesiculopustular lesions in the oral cavity should raise clinical suspicion. Histopathological examination via biopsy remains the gold standard for definitive diagnosis. Treatment is typically straightforward, with an excellent prognosis when managed appropriately.