Background: Periapical lesions (PLs) are the most frequently observed pathologies associated with alveolar bone. Ultrasound (US) is a non-invasive, inexpensive and painless imaging method. Unlike X-rays, it does not cause harmful ionizing radiation. US can be used for both hard and soft tissue detection. Hence; we planned this study to evaluate the diagnostic capability ultrasound imaging in the identifying and making differential diagnosis of PLs. Materials & methods: The present study included assessment of 20 patients of age 18 to 60 years who were found to have peri-apical lesions on radiograph. All the subjects underwent ultrasonographic examination. All the examinations including real-time and Color Doppler imaging were performed in the periapical area extraorally. The ultrasonographic images were analyzed based on the following principles as mentioned by previous authors. All the results were recorded and analyzed. Student t test and univariate analysis was used for the assessment of level of significance. Results: On histopathology examination, 18 cases were found to be peri-radicular cyst out of which 15 cases were reported to be peri-radicular cyst on ultra-sonography. Correlation was found in 15 cases of peri-apical radicular cysts. In case of peri-granuloma, correlation was observed only in one case.Conclusion: In comparison to conventional radiography, ultrasonography appears as a better imaging modality in the diagnosis of peri-apical lesions. Key words: Diagnosis, Peri-apical, Ultrasonogrpahy