Leg length discrepancy (LLD) is a common and often distressing complication following total hip arthroplasty (THA), impacting both functional outcomes and patient satisfaction. This chapter explores the causes, implications, and management strategies for LLD, focusing on revision THA for LLD. LLD can be categorized into anatomic LLD (ALLD) and functional LLD (FLLD), each requiring tailored approaches for optimal management. ALLD typically arises from surgical factors such as implant selection or surgical technique, while FLLD is attributed to non-hip factors like muscle imbalance or pelvic tilt. Management strategies encompass preoperative templating, intraoperative measurements, and postoperative rehabilitation. Surgical interventions are considered for cases of severe or symptomatic LLD, including femoral head shortening or revision surgery. By addressing LLD comprehensively and individualizing interventions, surgeons can enhance postoperative function and patient satisfaction in THA.