Abstract: AIM: To investigate the relationship between baseline hemoglobin and contrast-induced nephropathy (CIN) after coronary angiography and percutaneous coronary intervention. METHODS: A total of 1386 patients had undergone coronary angiography and coronary intervention procedure between October 2005 and November 2007. Serum creatinine concentrations were measured before and within 48 h of administration of contrast agents and further measurements were performed in all CIN patients. CIN was defined as an increase in serum creatinine concentration of 5 mg/L from preprocedure values. RESULTS: Among the 1386 patients, 29 (2.1%) experienced CIN after the procedure and 26.8% of patients with baseline creatinine clearance <60 ml/min had anemia. The incidence of CIN in patients with baseline creatinine clearance <30 ml/min was 22.3% in anemic patients and 14.8% in non-anemic patients. Anemia increased the risk of CIN in patients with baseline creatinine clearance 30-59 ml/min (5.8% vs.2.8%; P<0.05). The amount of the contrast agent administered was similar for CIN and non-CIN patients ［(160±72)ml vs.(148±68)ml; P>0.05］. Multivariate logistic regression analysis showed that baseline creatinine clearance, baseline hemoglobin and diuretic medications were independent predictors of CIN. When presence of anemia was introduced into the multivariate model instead of baseline hemoglobin, anemia was also found as an independent predictor of CIN (OR 2.765, 95%CI 1.486 to 3.657, P<0.01). CONCLUSION: The overall incidence of CIN after exposure to contrast medium is low (2.1%). Patients with both preexisting renal insufficiency and anemia are at high risk of CIN. Anemia increases the incidence of CIN in patients with moderate renal dysfunction. Baseline creatinine clearance, baseline hemoglobin (or anemia) and diuretic medications are independent predictors of CIN.