The use of B-type natriuretic peptide to diagnose congestive heart failure is becoming more frequent and widespread. We report five patients recently seen at our hospital who were diagnosed with pulmonary embolism and noted to have elevated B-type natriuretic peptide levels. We caution that elevations of B-type natriuretic peptide may in some patients have the potential to mislead clinicians if the diagnosis of pulmonary embolism is not considered.