Objective: Epidemiologic studies have shown that, compared to men, women have better prognoses in chronic renal diseases. This indicates that gender hormones may have some effect on renal function. The present study aimed to investigate the expression and relationship with prognosis of estrogen receptor alpha (ERα) in renal tissue of immunoglobulin A nephropathy (IgAN) patients. Methods: Expression of ERα was detected by immunohistochemistry. Specimens were collected from forty-five IgAN patients and five normal healthy participants. In addition to expression, the relationship of ERα with clinical data, prognosis, and the degree of glomerular damage were analyzed. Results: ERα was expressed in the glomeruli and renal tubules. The expression of ERα in the glomeruli of IgAN renal tissue decreased gradually ( P = 0.001, P < 0.05) with the increasing severity of disease and its expression was associated with estimated glomerular filtration rate (eGFR), serum creatinine (Scr) and pathological grade (r = 0.876, -0.818 and -0.736, P < 0.05). In addition, the expression of ERα was significantly decreased in hypertensive IgAN patients compared with the non-hypertensive group ( P = 0.011). We found that ERα was of great significance for the prognosis of IgAN ( P = 0.01, P < 0.05). Conclusions: The expression of ERα in the renal tissue of IgAN patients was reduced and there was a correlation with the degree of kidney damage and prognosis, suggesting that ERα may play a role in the progression of IgAN.