Acquired scrotal giant muscular hamartoma is an uncommon benign lesion with fewer than 10 documented cases all over the world. It is characterized by a proliferation of dermal smooth muscle bundles of scrotum dartos fascia. The authors report a rare case of acquired scrotal giant muscular hamartoma, which occurred in a 70-year-old severely obese and diabetic man presenting with a progressive scrotal enlargement and swelling in the last year, causing marked reduction in quality of life and cosmetic problems. The patient underwent a wide excision of the hamartomatous lesion, and then, a reductive scrotoplasty and autologous skin grafting of penis were performed. Anatomopathological examination showed an acquired scrotal giant muscular hamartoma arising from muscular fascia of dartos. This surgical technique is a valid, safe, effective, and minimally invasive option to treat this pathology, achieving both excellent functional and aesthetic results, with a marked improvement of the patient’s quality of life.