Perianal Paget’s disease is a rare intraepithelial adenocarcinoma of the anal margin. Because of its rarity, delay in diagnosis is common and requires a high index of suspicion. Although its etiology has never been definitively determined, it now appears that 2 types of perianal Paget’s disease exist. Primary perianal Paget’s disease likely represents intra-epithelial neoplasm from an apocrine source, whereas secondary disease may represent “pagetoid” spread from an anorectal malignancy. Diagnosis of the 2 types of disease can be established from distinct immunohistochemical stain patterns. Wide local excision remains the treatment of choice for primary disease, with or without local invasion. Although local recurrence is high, re-excision can still be curative. Treatment of secondary disease is less clear, though aggressive therapy appears indicated for curative intent. Although adjuvant therapy is desirable, experience is still very limited.