Plasma D-dimer measurement is the first diagnostic test performed in patients with a non-high or an unlikely clinical probability of pulmonary embolism (PE) but its clinical usefulness is limited in elderly patients due to a low specificity in this subgroup. PE can be excluded based on D-dimers and clinical probability only in about 5% of patients over 80 years when using the conventional cut-off. Age-adjusted D-dimer cut-off (adjusted cut-off value = age x 10 in patients over 50) increases the specificity of the test without significantly reducing its sensitivity. Using the age-adjusted D-dimer cut-off markedly reduces the need for further diagnostic studies such as computed tomography pulmonary angiography (CTPA). The age-adjusted cut-off has been widely validated in retrospective cohorts, and more recently in a prospective management study.