Over the past two decades, sonography has assumed a primary role in the evaluation of a wide variety of non-obstructive renal parenchymal disorders in the paediatric age group. Our study showed that the problem of non-obstructive renal parenchymal diseases is a diffuse increase in the echogenicity of the parenchyma. If a specific diagnosis cannot be made after clinical evaluation or if a systemic disease is not identified, a renal biopsy is needed and it has a very low complication rate if it is sonographically guided. It was found that the hallmark of non-obstructive renal parenchymal diseases is a diffuse increase in echogenicity throughout the parenchyma of both kidneys. The sonographic detectability of the corticomedullary junction and the renal pyramids may be affected by the histopathological changes. Unfortunately sonography usually cannot render a tissue specific diagnosis. Ultrasonography is a valuable tool in the evaluation of different non-obstructive renal parenchymal diseases. Colour Doppler sonography helps in the diagnosis and characterization of non-obstructive renal parenchymal diseases. It may show increased RI in different diseases of the kidney, however, this increase is non-specific. Computed tomography is one of the best imaging modalities of the reteroperitoneal structures. The present study has shown that CT nephrogram is valuable mainly in certain categories of non-obstructive renal parenchymal diseases. CT nephrogram presents no characteristic morphological findings in glomerular diseases such as glomerulonephritis. CT is an excellent modality for detecting masses and assessing renal trauma. It is of value in detecting renal infiltration, but cannot point to specific pathological diagnosis. The revolution of the helical CT technology has made it the best modality for imaging of acute renal vascular disorders and in creating multiplanar and three-dimensional images that are of sufficient quality to be useful in imaging the renal arteries by CT angiography in cases of suspected renal artery stenosis. A large number of publications pointed out the importance of CT in assessment of renal masses, in diagnosis and staging of renal tumours and in surgical planning of such cases.