Interstitial lung disease comprises a heterogeneous group of disorders in which there is a predominantly restrictive pattern of lung disease. It is characterized by derangement of alveolar walls and the loss of alveolar-capillary units and variable degree of fibrosis which results in destruction of pulmonary vascular bed, oxygen diffusion impairment and hypoxic pulmonary vasoconstriction that will lead to pulmonary hypertension. Aim: To identify the added value of Cardiac Magnetic Resonance Imaging thresholds for assessment of pulmonary hypertension and right ventricular function in Pediatric interstitial lung disease complicated by pulmonary hypertension. Methods: A total number of 34 cases, both males and females, less than 18 years old known to have interstitial lung disease proved clinically and radiologically complicated by pulmonary hypertension were included in this study. By using 1.5 T CMR scanner equipped with 32 channel cardiac coils, we performed steady-state free precession cine CMR to assess the right ventricular function. Other risk stratification tools of pulmonary hypertension (echocardiography-Pro BNP- 6 MWT- speckle tracking Doppler) were also done. The study group assessed initially and follow up done after a period of 6 months of treatment. Results: The study group consisted of 34 cases; 13 males (38.2 %) and 21 females (61.8%). The mean age was 8.22 ± 4.22 years old. The mean estimated systolic pulmonary artery pressure (ESPAP) pressure was 67.80 ± 27.40mmHg detected by echocardiography. The mean right ventricular ejection fraction (RVEF) detected by cardiac MRI was 50.33 ± 9.30%. By comparing the initial and the follow up group, there was statistically significant difference regarding ESPAP (p=0.044), EDPAP (p=0.017), RVEDV by CMR (p=0.022) and RVESV by CMR (p=0.030). There was negative correlation between RVEF by CMR and systolic pulmonary artery pressure (ESPAP) (r=-0.522 & p=0.002) and GLS in the speckle Doppler (r=-0.412 & p=0.019). Univariate linear regression analysis for the initial parameters affecting RVEF by CMR revealed that it is affected by (O2 saturation, systolic and diastolic pulmonary pressures, right ventricular and atrial dilatation and global longitudinal strain in speckle tracking Doppler). Conclusion: The current study demonstrated the added value of cardiac MRI in assessment of right ventricular function in childhood interstitial lung disease complicated by pulmonary hypertension. CMR derived right ventricular ejection fraction (RVEF) might be useful for the risk stratification and clinical management of ILD patients.