Introduction. Pulmonary thromboembolism (PTE) is not an uncommon cause of sudden, unexpected death. Autopsy is the gold standard for cause of death determination in cases of suspected PTE. Mortality rates due to PTE are not estimated accurately. Objective. The aim of this study was to analyze distribution patterns and risk factors of sudden deaths due to PTE. Methods. Retrospective analysis of Lithuanian State Forensic Medicine Service autopsy data, period 2014-2018. A total of 4533 cases were reviewed; 80 cases met the criteria of immediate cause of death being PTE and were included in the study. PTE epidemiology, risk factors, clinical and pathoanatomical characteristics were described by reviewing scientific literature and statistical databases. Results. PTE as the cause of sudden death was diagnosed in 37(46.25%) men and 43(53.75%) women. Median age at the time of death was 62.8±17.2 years. Death occurred in hospital in 21(26.25%) cases. Trauma was the underlying cause of PTE in 11(13.75%) cases; 9(81.8%) patients were admitted to hospital after a traumatic event. Cardiac hypertrophy was observed in 70(87.5%) autopsies. Abdominal subcutaneous fat thickness was 4.08±2.64 cm in men and 5.35±2.69 cm in women. Deep vein thrombosis (DVT) was confirmed upon microscopic examination in all cases, being the underlying cause of death in 67(83.75%) cases. Conclusion. Sudden death due to PTE usually occurs at an older age and in absence of medical care. PTE is common after sustaining severe traumatic injuries which, when not immediately lethal, are managed in hospital. Cardiac hypertrophy and obesity may increase risk of death due to PTE. Undiagnosed and untreated DVT is often the underlying cause of sudden death due to PTE.