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Death

Johnson died on August 16, 1938, at the age of 27, near Greenwood, Mississippi, of unknown causes. Johnson's death was not reported publicly. Almost 30 years later, Gayle Dean Wardlow, a Mississippi-based musicologist researching Johnson's life, found Johnson's death certificate, which listed only the date and location, with no official cause of death. No formal autopsy had been done. Instead, a pro forma examination was done to file the death certificate, and no immediate cause of death was determined. It is likely he had congenital syphilis and it was suspected later by medical professionals that this may have been a contributing factor in his death. However, 30 years of local oral tradition had, like the rest of his life story, built a legend which has filled in gaps in the scant historical record.

Several differing accounts have described the events preceding his death. Johnson had been playing for a few weeks at a country dance in a town about 15 miles (24 km) from Greenwood. According to one theory, Johnson was murdered by the jealous husband of a woman with whom he had flirted. In an account by the blues musician Sonny Boy Williamson, Johnson had been flirting with a married woman at a dance, and she gave him a bottle of whiskey poisoned by her husband. When Johnson took the bottle, Williamson knocked it out of his hand, admonishing him to never drink from a bottle that he had not personally seen opened. Johnson replied, "Don't ever knock a bottle out of my hand." Soon after, he was offered another (poisoned) bottle and accepted it. Johnson is reported to have begun feeling ill the evening after and had to be helped back to his room in the early morning hours. Over the next three days his condition steadily worsened. Witnesses reported that he died in a convulsive state of severe pain. The musicologist Robert "Mack" McCormick claimed to have tracked down the man who murdered Johnson and to have obtained a confession from him in a personal interview, but he declined to reveal the man's name.

While strychnine has been suggested as the poison that killed Johnson, at least one scholar has disputed the notion. Tom Graves, in his book Crossroads: The Life and Afterlife of Blues Legend Robert Johnson, relies on expert testimony from toxicologists to argue that strychnine has such a distinctive odor and taste that it cannot be disguised, even in strong liquor. Graves also claims that a significant amount of strychnine would have to be consumed in one sitting to be fatal, and that death from the poison would occur within hours, not days.

In their 2019 book Up Jumped the Devil, Bruce Conforth and Gayle Dean Wardlow suggest that the poison was naphthalene, from dissolved mothballs. This was "a common way of poisoning people in the rural South", but was rarely fatal. However, Johnson had been diagnosed with an ulcer and with esophageal varices, and the poison was sufficient to cause them to hemorrhage. He died after two days of severe abdominal pain, vomiting, and bleeding from the mouth.

The Leflore County registrar, Cornelia Jordan, years later and after conducting an investigation into Johnson's death for the state director of vital statistics, R. N. Whitfield, wrote a clarifying note on the back of Johnson's death certificate:

I talked with the white man on whose place this negro died and I also talked with a negro woman on the place. The plantation owner said the negro man, seemingly about 26 years old, came from Tunica two or three weeks before he died to play banjo at a negro dance given there on the plantation. He stayed in the house with some of the negroes saying he wanted to pick cotton. The white man did not have a doctor for this negro as he had not worked for him. He was buried in a homemade coffin furnished by the county. The plantation owner said it was his opinion that the man died of syphilis.

In 2006, a medical practitioner, David Connell, suggested, on the basis of photographs showing Johnson's "unnaturally long fingers" and "one bad eye", that Johnson may have had Marfan syndrome, which could have both affected his guitar playing and contributed to his death due to aortic dissection.