Anemia is common in patients admitted for acute coronary syndrome and is associated with an increased risk of death and adverse outcomes. The aim of this study was to assess the impact of baseline haemoglobin levels on major bleeding complications six-month mortality in patients with non ST segment elevation myocardial infarction (NSTEMI). A total of 340 patients with NSTEMI in the cardiology B department were enrolled. The diagnosis of anemia was made on a baseline hemoglobin < 13 g/dl for men and < 12 g/dl for women. The primary end points were major adverse cardiac events (MACE) and major bleeding assessed at 6 months. The association between baseline haemoglobin and major bleeding and/or MACE was examined. Among 340 patients, 80 (23.5%) had anemia at baseline. All-cause death at 6 months (8.75% vs. 1.53%; P = 0.04), major bleeding (10% vs. 0.8%; P = 0.001) were more common in patients with baseline anemia. Anemia was an independent predictor of six-month mortality (OR 6.24; 95% CI 1.77–21.9; P = 0,001). Anemia was an independent predictor of the risk of major bleeding in NSTEMI as well as of the risk of MACE and six-month mortality. Thus, baseline anemia should be taken into account in patients presenting with NSTEMI.