A consecutive series of 100 patients undergoing primary total hip arthroplasty were assessed for functional leg-length inequality (FLLI). In addition, the medical records of all patients treated for FLLI by the senior author (C.S.R.) in the past 15 years was reviewed. A questionnaire was distributed to the members of the Hip Society specifically to query the prevalence, etiology, and management of FLLI. Fourteen percent of patients were noted to have pelvic obliquity and FLLI.1 month after surgery. All had resolution of the symptoms by 6 months after surgery. Nine patients have been identified over the past 15 years with persistent FLLI. Among the causes suggested by respondents to the questionnaire are tightness of periarticular soft tissues with resultant pelvic obliquity and degenerative conditions of the spine with contracture. Methods of treatment and prevention are discussed.