Background: Cardiac magnetic resonance imaging (CMR) is a valuable assessment tool for assessment of hypertrophic cardiomyopathy (HCM). Many advanced sequences is rapidly developing. Objective: To assess the value of Cardiac MRI In diagnosis, Follow Up and Post-management evaluation of hypertrophic cardiomyopathy. Patients and Methods: A diagnostic test accuracy study with prospective evaluation was performed in Cardiology Department of Kobry Elkobba Military Medical Complex and Radiology and Medical Imaging Department of Magdy Yacoup Heart Foundation. Cardiac MRI was done for 50 patients who were screened for HCM, were suspected to have HCM by clinical and echocardiographic examination and some come for follow up. Results: 74% of the cases had asymmetrical septal hypertrophy. 40% of the cases had systolic anterior motion of the mitral valve leaflet (SAM). 28% of the patients had left ventricular outflow obstruction (LVOTO), 85.7% of them had asymmetric septal phenotype and all had SAM. 18% of the cases had systolic midventricular obliteration (MVO), and all of them had mid ventricular phenotype. 62.1% of the cardiac segments exhibited extracellular volume (ECV) expansion with no evident LGE with significant P-value (0.009). Follow up of the 6 patients underwent septal myomectomy revealed that left ventricular thickness range decreased from 22 to 26 mm to 18 to 24 after the operation. The SAM, mitral regurge and LVOTO resoluted in most of cases. Conclusions: MRI is a crucial technique for diagnosis, follow up and risk stratification for patients with suspected or diagnosed to have HCM.