Perianal Bowen’s disease is a rare disease, diagnosed on the basis of suspicion and histologic examination. Although in gross appearance the lesion can mimic other anorectal conditions, such as condyloma acuminatum, psoriasis, neurodermatitis, leukoplakia, extramammary Paget’s disease, moniliasis, and seborrheic dermatitis, the histologic picture is distinctive and characteristic. A careful search must be made for other malignancies, as they may occur in 40 per cent of these patients. The treatment of choice is complete excision, with multiple histologic sections, reserving radical surgery for invasion and metastasis. Careful long-term follow up is imperative, as there is a strong possibility of recurrence.