The prognostic implications of NT-proBNP measured on admission in patients with the ST-elevation myocardial infarction (STEMI) are not so far well elucidated. The present investigation, performed in 198 STEMI patients submitted to percutaneous coronary intervention (PCI), was aimed at assessing the prognostic value of NT-proBNP measured on admission to Intensive Cardiac Care Unit (ICCU) and its relation with the extension of myocardial infarction (indicated by cardiac biomarkers and ejection fraction) and inflammatory markers (C-reactive protein - CRP, erythrocyte sedimentation rate - ESR, leucocytes, fibrinogen). All patients who died during ICCU stay had increased values of NT-proBNP. Each quartile of NT-proBNP resulted directly correlated with age, heart rate, peak Tn I, admission creatinine serum levels, ESR, fibrinogen, and inversely correlated with ejection fraction. At backward logistic regression analysis, NT-proBNP values showed a significative correlation with peak Tn I (OR 1.013; 95% CI 1.001-1.025; p=0.036), and CRP positive (OR 6.450; 95% CI 1.714-24.272; p=0.006); age was close to reaching statistical significance (OR 1.043; 95% CI 0.999-1.089; p=0.055). At long term-follow-up NT-proBNP lacks any prognostic role in predicting adverse events such as hospitalization for rePCI, re-infarction and heart failure. Kaplan-Meier curves showed that all patients dead at follow-up were in the highest NT-proBNP quartiles.