Everolimus, a mammalian target of rapamycin inhibitor, is an emerging drug, which is being increasingly applied in oncology and solid organ transplantation. Oral ulcers are a frequent side effect associated with this immunosupressor. We report the case of a renal transplant recipient who developed disfiguring oral and perianal ulcers secondary to everolimus's toxicity. This is probably the first report of perianal involvement. Dermatologists need to be aware of the potential mucocutaneous adverse effects related to these new drugs that are becoming evermore common in our clinical practice.