: Osteoporotic vertebral fractures in older patients cause lower back pain and abnormal posture, resulting in impaired activities of daily living (ADLs). Assessing pain using self-reported assessment tools is difficult, especially in patients with moderate-to-severe cognitive impairment. Recently, observational assessment tools have been used when self-reported ones were difficult to administer. No studies have reported the usefulness of observational assessment tools in patients with acute-phase orthopedic disorders without complication. This study aimed to examine the availability of observational tools for pain assessment in patients with lumbar vertebral fractures. : Patients admitted to our hospital with acute-phase vertebral fractures were enrolled in this prospective observational study. Pain was assessed using Japanese versions of the Abbey pain scale and Doloplus-2 observational assessment tools, and the Numerical Rating Scale, a self-reported assessment tool. To compare the pain assessment tool, we examined whether each tool correlated with ADLs and ambulatory status. ADLs were assessed using the Barthel Index. Ambulatory status was assessed using the Functional Ambulation Categories and the 10-m walking test. : Similar to the Numerical Rating Scale scores, assessments with the Abbey pain scale and Doloplus-2 showed significant decreases in scores over time. A significant positive correlation was observed between the self-reported and observational assessment tools. Each pain assessment tool was significantly negatively correlated with ADLs and ambulatory status. : When self-reported assessment with the Numerical Rating Scale is difficult for patients with cognitive impairment, pain can be estimated using the Abbey pain scale and Doloplus-2 observational assessment tools.