Background: Spinal intradural mass lesions represent a challenge in microsurgical practice. Intraoperative precise localization and characterization of these lesions must be achieved to avoid excessive exposure and neural tissue damage. This study aims to evaluate the role of intraoperative ultrasound during surgical dealing with spinal intradural mass lesions starting before bone work. Methods: This prospective study was done at Neurosurgery Department, Zagazig University Hospitals, Egypt, during the period from January 2022 to January 2023 with follow up at least 6 months on 36 patients suffering from spinal intradural mass lesions who underwent microsurgical intervention aided with intraoperative ultrasound. Spine MRI and Klekamp score were used as preoperative and postoperative parameters for assessment of the patients. Intraoperative ultrasound features were analyzed to evaluate its value. Results: All lesions were visualized and characterized by intraoperative ultrasound beside spinal anatomical identification. Laminoplasty/ laminectomy, durotomy and myelotomy were determined by intraoperative ultrasound. Gross total eradication was achieved in 28/36 (78%). Intraoperative ultrasonographic identification of cystic component, well defined borders and smooth shape of the mass were associated with significant Klekamp outcome improvement. Conclusion: Intraoperative ultrasound can be used safely to detect spinal intradural mass lesions even before bony work for exposure with effective anatomical and pathological identification and can predict the outcome. Key words: Intraoperative ultrasound, intradural spinal mass, intramedullary spinal lesions, ultrasound spinal