An autopsy report or autopsy file was a type of report that described the findings of an autopsy.
After passing through the galactic barrier, the USS Enterprise's life sciences division performed autopsies on the nine crewman who had died. The conclusion, as summarized in the reports, was that each person suffered damage to their body's neural circuit as areas of their brains had been burned out. (TOS: "Where No Man Has Gone Before")
In 2367, Beverly Crusher studied the autopsy reports of the USS Brattain crew and came to the conclusion that all 34 of them appeared to have killed each other, which she found appalling. (TNG: "Night Terrors")
In 2369, Crusher tried to access USS Enterprise-D's autopsy files for Reyga and Jo'Bril, but not being active, she was unable to do so. Alyssa Ogawa, overhearing this, asked what she wanted to access the files for. When Crusher apologized for being in sickbay when she had been relieved of duty, Ogawa accessed the files instead, and helped Crusher check the records for suspicious details. (TNG: "Suspicions")
In 2372, The Doctor stated that he could quote autopsy reports from duels between men for the love of women as far back as 1538. (VOY: "Parturition")
The Doctor's knowledge of such dated reports in his program implies that such information is also available from the Starfleet Medical Database.