Circumferential acquired macropenis is a rare syndrome of symmetric corpora cavernosa girth increase, that encompasses two distinct etiologies: post-priapistic cases, with penile girth increase both in flaccidity and erection, and idiopathic cases, with girth increase in erection only, and a thinned albuginea in the affected area (paper accepted for publication - Sexual Medicine). We propose an “ad hoc” geometrically-based reduction corporoplasty. Case: man that developed over two years a critical girth penile increase up to 21 cm, causing partner dyspareunia. DICC ruled out vascular problems; its cavernosographic phase showed a symmetric, sharp dilatation of the two corpora at the shaft middle 2/3 (see Figure). Surgical technique: following neurovascular bundle elevation, proximal and distal normal, “target” circumferences, according to perception of normal thickness albuginea, are measured. Bilateral paraurethral defined reference intervals are marked along the dilated aspect of the albuginea; circumferential measurements at such reference sections are performed. The differences between the measured circumferences and the target circumferences are then calculated. Each resulting difference is divided by two, to identify the final measurements to bilaterally define the ellipses of albuginea to be excised. Following their removal, albugineal margins are closed with a continuous water-tight suture. In all the affected aneurysmal area the thinned albuginea is reinforced by a patch of bovine pericardium (Synovis Supple Peri-Guard®), fashioned according to the target erect shaft dimensions, and anchored with cardinal stitches at the paraurethral albuginea, and in the dorsal midline.Bucks’ fascia is re-approximated, and standard circumcision performed. At 20 months follow-up the patient is maintaining a normalized penile shape, he has a regular sexual activity, with dyspareunia resolution and full patient-partner satisfaction. Circumferential acquired macropenis prevents affected men from effective sexual penetration. We present its correction by a geometrically-based reduction corporoplasty, with satisfactory results at 20 months follow-up. Authors do not have any conflict of interest.