Markers for hypercoagulation can be used to explain why some patients may have had thromboembolic disease (TED). This information may then be applied to estimate risk for additional TED that may afflict these patients following subsequent surgeries. This investigation was to determine the frequency of hypercoagulation parameters among patients having had TED, and how frequently these occur in multiples. Consulting hematologists were asked to comment upon potential risk for recurrent TED that may be associated with additional surgeries. The consulting hematologist determined which laboratory tests were to be ordered for each patient. This retrospective study probed the hospital computer logs for patients having had homocysteine, protein C, factor V Leiden or anticardiolipin antibodies measured during a 6-year period. The laboratory records for patients having had any one of these tests were then examined further for any additional hypercoagulation laboratory studies performed. Five hundred and twenty patients were identified in this survey. Abnormal diagnostic results were found for 293 (56.3%) of these patients. Two or more abnormalities (up to 5) were found for 103 (35.6%) of these patients. Laboratory explanations for TED may be found in a large proportion of patients with TED. It is not uncommon to find more than one abnormality among these patients. This information may be used in advising patients and their physicians as to the risks of additional TED following future surgical procedures and can be the basis for recommending life style changes.