Background: Optical Coherence Tomography is a very sensitive modality for detection of even subclinical macular edema and provides both qualitative and quantitative results used in monitoring and follow up of patients before and after treatment of ME. However, B-Scan Ultrasonography is a non-Invasive diagnostic tool that has the advantage of reliably imaging the posterior segment regardless of the ocular media status and it is less dependent on patient cooperation. Aim of the Work: To report sensitivity and specificity of B-scan Ultrasonography in detection of macular edema. Patients and methods: This observational case series was conducted on Forty eyes of 20 patients examined at the ophthalmology clinic of Cairo Fatimic Hospital. They were asked to participate and were enrolled in this study in the period from December 2017 to March 2018. Results: There was high degree of agreement between clinical diagnosis and echographic findings of macular thickening. The sensitivity and positive predictive value (PPV) of B-scan ultrasonography to detect ME were 91.7% (22/24) and 84.6% (22/26) respectively. The specificity and negative predictive value (NPV) of B-scan ultrasonography to detect ME were 75% (12/16) and 85.7% (12/14), respectively. And consequently, the diagnostic accuracy of B-scan ultrasonography to diagnose ME was found to be 85% (34/40). Conclusion: Optical Coherence Tomography is the most sensitive method to diagnose macular edema both qualitatively and quantitatively, but in certain circumstances when performing OCT would be difficult or even impossible, B-Scan Ultrasonography provides an acceptable method to qualitatively detect macular edema.