Horses with extensive or invasive tumors of the external genitalia may require surgical intervention for successful treatment. Solitary tumors may be removed completely by local excision, laser ablation, cryotherapy, or circumferential posthectomy (i.e., reefing). Horses with advanced lesions involving the glans or body of the penis warrant phallectomy, whereas horses with infiltrative lesions of the penis and prepuce with suspected or confirmed metastasis to lymph nodes require en bloc resection and penile retroversion. This article describes the indications, procedures, aftercare, and potential complications for each surgical technique, Anticancer drugs administered perioperatively may improve outcome in select cases, and indications for their use are discussed as well.