Case reports have indicated that pulmonary embolism (PE) can be associated with deaths during episodes of catatonia. A 15-year death registry in Kentucky state psychiatric hospitals was reviewed for deaths during episodes of catatonia. From 2002 to May of 2016, reports of 96 deaths at these state psychiatric hospitals were found and reviewed by the state mortality committee. The charts of the identified catatonic patients were thoroughly reviewed. All 6 deaths occurred during episodes of what Fink and Taylor would call retarded catatonia and Ungvari would call acute stuporous catatonia. The deaths were sudden and appeared to be explained by PE. They accounted for 6% (6/96) of the state hospital deaths. Moreover, they explained 32% (6/19) of the deaths that the committee considered preventable at some level, making pulmonary embolism by far the most important cause of preventable deaths. Catatonia diagnosis and treatment were far from optimal. The stupor in these 6 patients lasted many weeks with a median duration of catatonic symptoms while hospitalized of 45 days in the total sample and 75 days in four patients who died suddenly. If replicated in other mortality databases from other states or countries, two lessons in prevention of these PE deaths in catatonia would be the urgent needs to: 1) improve the skills of clinicians (psychiatrists and internists) for diagnosing and treating stuporous episodes of catatonia and 2) quickly and aggressively treat stuporous episodes of catatonia.