Background: There has been concern that women may be limited to fewer major diagnostic tests than men. Whether this applies to patients with pulmonary embolism (PE) or deep venous thrombosis (DVT) has not been determined. Objective: To assess whether there is a sex disparity in the application of diagnostic tests for PE or DVT, in reaching a diagnosis, or in using medical facilities. Design: A study of cross-sectional samples of hospitalizations from 21 separate years using data from the National Hospital Discharge Survey. Setting: Noninstitutional hospitals in the 50 states and the District of Columbia from 1979 through 1999. Patients: The National Hospital Discharge Survey abstracts demographic and medical information from the medical records of inpatients. For 1979 through 1999, the number of patients sampled ranged from 181000 to 307000. Measurements: The number of sampled patients with DVT and with PE and the number of diagnostic tests performed were determined from the International Classification of Diseases, Ninth Revision, Clinical Modification codes at discharge. A multistage estimation procedure gave an estimation of values for the entire United States. Results: Age-adjusted rates of the diagnosis of PE per 100000 population and of DVT per 100000 population were not lower in women. Rates of the use of ventilation-perfusion lung scans, venous ultrasonography of the lower extremities, and contrast venography were not lower in women. Durations of hospitalization for PE or DVT were comparable in men and women. Conclusion: Data from the National Hospital Discharge Survey do not support a sex bias in the diagnosis of PE or DVT, the use of diagnostic tests, or the duration of hospitalization for PE or DVT.