INTRODUCTION: Trochanteric fractures are one of the most common fragility fractures, and the number of the patients is increasing worldwide. Identifying prognostic factors is important to manage and minimize the social losses caused by postoperative walking impairment. The purpose of this retrospective study is to clarify the association between early postoperative Barthel index score and postoperative long-term walking ability among patients with trochanteric fractures who could walk independently before injury. MATERIALS AND METHODS: Consecutive patients with trochanteric fractures aged ≥ 65 years who were walking independently before injury were included. Patients were divided into two groups according to the Barthel index score measured within 1 week after surgery; the cut-off value was set at 20 points. The prevalence of walking impairment after 1 year was compared between these two groups after adjusting for confounding factors in a complete case analysis and using the data introduced by the multiple imputation method. RESULTS: Among the 758 eligible patients, 254 patients (34%) had their walking ability evaluated after 1 year from injury. The patients in the lower Barthel index group showed a significantly impaired walking ability in both analyses (adjusted odds ratio 5.5 and 2.4, 95% confidence intervals 2.4-13 and 1.5-3.8, respectively). CONCLUSIONS: The present results suggested that the Barthel index score measured in the early postoperative period after trochanteric fractures was associated with the level of long-term walking impairment in patients who could walk independently before injury.