Penile girth enhancement (PGE) using hyaluronic acid (HA) fillers has emerged as a safe, reversible, and highly effective technique for men seeking both aesthetic and functional improvement. While clinical studies have demonstrated its efficacy and favorable safety profile, real-world outcomes are largely determined by the clinician’s technical expertise and patient management strategies. This chapter synthesizes over 25 years of clinical experience with HA-based PGE, presenting practical insights, technical refinements, and solutions to common complications. Detailed discussion of filler properties, injection methods, patient selection, and post-procedural care aims to guide practitioners toward consistently successful outcomes. Emphasis is placed on avoiding pitfalls such as filler migration, asymmetry, and patient dissatisfaction, ensuring that PGE becomes a predictable and rewarding component of andrological practice.