Detectives found the communication while investigating Cobain's death 20 years ago, but have never released it until now.
The note suggests Cobain and the Hole star had fallen out, but it isn't clear if the All Apologies singer had presented it to his wife or not.
It reads: "Do you Kurt Cobain take Courtney Michelle Love to be your lawful shredded wife. even when she's a b**ch with zits (acne) and siphoning all yr (your) money for doping and whoring..."
The note, written on stationery from a San Francisco-area hotel, has a completely different tone to Cobain's suicide note, in which he calls Love a "goddess of a wife" who "sweats ambition and empathy".
A recent review of the case led lawmakers to rule that the King County Medical Examiner's original determination that Cobain's death was a suicide was correct. The rocker shot himself after taking a lethal dose of heroin.
In a new clip from the forthcoming official Kurt Cobain documentary, we discover the birth...