In Wistar male rats, hypertension was induced by 5/6 nephrectomy (5/6N). Body weight, blood pressure measurements, morphological and biochemical changes were followed (at four weekly intervals) for 12 weeks after 5/6N. Renal function was assessed by daily total urinary protein (TUP), plasma creatinine concentration [(Cr)p] and creatinine clearance rate. Plasma renin concentration (PRC), aldosterone concentration and erythrocyte content of sodium [Na]E and potassium [K]E were also investigated. Significant increases in systolic blood pressure (SBP), TUP, [(Cr)p] and [Na]E occurred after 4, 8, and 12 weeks of 5/6N. Progressive glomerulosclerosis (GSC), tubular atrophy and interstitial fibrosis were observed. Positive correlations were found between GSC and SBP and TUP. Positive correlations were also found between SBP and [Na]E and [(Cr)P]. PRC was not increased and showed no correlation with SBP. It is concluded that 5/6N produced hypertension associated with a series of morphological and biochemical alterations in kidney structure and function. In this model, mechanisms other than the renin‐angiotensin system may be involved.