Gingival inflammation is highly prevalent among adult populations in all regions of the world. High rates of chronic periodontitis have been reported worldwide. The methods for assessing the gingival inflammation and periodontal disease would need more precision and less user-dependence. The aim of this study consists in identifying the information for diagnosis and staging of periodontal disease using 40 MHz periodontal ultrasonography. Our in vivo study has been made on 49 teeth of 10 patients with marginal periodontal disease. Standard clinical and radiological periodontal examinations were performed. Afterwards the results were compared with the information obtained from images recorded with Ultrasonix SonoTouch used at 40 MHz. On the ultrasound images, were performed very accurate measurements between the cortical bone and the cement-enamel junction or the root wall compared with the measurements made on intraoral digital radiographs. Those measurements could be used to diagnose the bone resorption. In order to monitor the gingival inflammation could be recorded the width of the attached gingival mucosa and the height of the gingival margin on ultrasound images. 40 MHz periodontal ultrasonography is a reliable imagistic method for identifying the necessary anatomical elements in order to make an accurate periodontal diagnosis for the examined area.