Mitchell wrote "A Case of You" in or before 1970. As with many of the songs on her album Blue, her break up with Graham Nash is often cited as the inspiration for the song. She performed the song at the Amchitka Greenpeace benefit concert in October 1970. She recorded the song in 1971, and it was released on the 1971 album Blue with Mitchell playing Appalachian dulcimer, accompanied by James Taylor on acoustic guitar.

Mitchell's earliest public performances of "A Case of You" contain six lines that had changed by the time Blue was recorded. Some of these nautical-flavored lines are: "Just before our ship got lost"; "'You're silly as a northern fish,' says I"; and "I drew a map of Canada and charted our last squall.". The line "I am as constant as a northern star" is an allusion to Caesar's "I am as constant as the Northern Star" from the Shakespeare play Julius Caesar.

"A Case of You" was also released as the B-side of "California".

Mitchell later re-recorded the song for her live album Miles of Aisles (1974), as well as her orchestral album Both Sides Now (2000).

She performed it regularly on her 1983 tour.

The original recording was included on Mitchell's compilation Misses (1996).

In 2011 Mitchell was voted the No. 1 female artist and "A Case of You" the No. 1 female song by listeners of BBC Radio 4's Desert Island Discs.

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