Renal dysplasia is defined as a condition of disorganised development of renal parenchyma due to abnormal differentiation. The case of a 5-month-old intact male Norwegian Forest Cat with a history of polyuria and polydipsia is reported. Ultrasonographic examination showed a slight enlargement of kidneys. Biochemical parameters, haematological examinations and clinical signs were compatible with chronic renal failure (CRF). Histological examination was correlated with a primary tubular disorganisation and modification of glomerular compartment. The clinical history together with the histological lesions is consistent with bilateral juvenile renal dysplasia in this cat. To our knowledge, feline renal dysplasia has been reported in fetal infections with panleukopenia virus; no reports indicate the idiopathic origin in feline dysplastic lesions.