Background: Atypical fibroxanthoma is a rare cutaneous tumour of mesenchymal origin, often presenting as a rapidly growing, painless mass in sun-exposed areas. Although historically considered benign, it has an intermediate malignant potential with a risk of recurrence and, in rare cases, metastasis. Treatment primarily involves surgical excision, although recurrence rates can occur. Adjuvant superficial high-dose-rate (HDR) brachytherapy (plesiotherapy) is able to reduce recurrence risk, particularly after local tumour relapses and/or when complete excision with wide margins is unfeasible. It provides excellent local control, cosmetic outcomes and minimal toxicity, making it a promising option in selected cases. This report highlights the utility of customised-mold HDR plesiotherapy for a locally recurrent atypical fibroxanthoma.