Sergio Mendes' cause of death has been revealed -- the Brazilian musician died from respiratory failure.
According to the death certificate, obtained by TMZ, the official cause of death is acute hypoxemic respiratory failure ... a condition that occurs when there's not enough oxygen in the body.
The condition can be brought on by pneumonia ... and Sergio's death certificate says aspiration pneumonia is an underlying cause here. This specific type of pneumonia is a lung infection resulting from food, liquid or other substances being inhaled into the lungs.
Sergio also suffered from a chronic lung disease that contributed to his death ... and his family has said he had been struggling with long-term COVID.
TMZ broke the story ... Sergio died September 5 in Los Angeles, and the death certificate says he passed at Providence Cedars-Sinai Tarzana Medical Center ... and he's since been cremated.
Sergio won 1 Grammy Award, 2 Latin Grammys, and was nominated for an Oscar in 2012 for the song "Real in Rio" featured in the animated movie "Rio" ... and the document lists his occupation as "music producer" and shouts out his 65 years in the music industry.
He was 83.