We conducted a prospective study in a pediatric cardiac intensive care unit in order to determine the diagnostic value of N-terminal brain natriuretic peptide (N-BNP) plasma concentration in the perioperative care of children with congenital heart disease (CHD). N-BNP plasma concentrations were determined by using a validated enzyme immunoassay. We measured N-BNP the day before surgery and up to 15 days postoperatively in 23 children (age range, 0.25-11 years) undergoing cardiac surgery due to various CHDs. Supply and duration of catecholamines, vasodilators, and respiratory therapy were determined and correlated to N-BNP. In addition, troponin T (TnT) and arterial Lactat (aL) concentrations were measured simultaneously. We found a significant correlation between preoperative and maximal N-BNP levels and dosage of vasodilators (r = 0.41, p < 0.02 and r = 0.83, p < 0.01, respectively). Maximal TnT and aL levels were not correlated to dosage of vasodilators. The dosage and duration of catecholamines, the duration of respiratory therapy, and the plasma concentration of TnT and aL were not correlated to pre- or perioperative N-BNP. Maximal TnT and aL levels were correlated to duration (r = 0.53, p < 0.01 and r = 0.48, p < 0.02) and dosage (r = 0.52, p < 0.02 and r = 0.60, p < 0.01) of catecholamines and duration of respiratory therapy (r = 0.57, p < 0.01 and r = 0.50, p < 0.02). As recent studies show, N-BNP appears to be a powerful neurohumoral indicator of ventricular function and prognosis for guiding therapy in the outpatient department or for discriminating cardiac from noncardiac symptoms. In contrast, the value of N-BNP for guiding perioperative therapy in pediatric cardiac intensive care units is limited.