The death of Wolfgang Amadeus Mozart was mysterious from the very first day, and cause of wildest speculation and adventurous assertions. Over the last 100 years, medical science has investigated the physical sufferings and the mysterious death of Mozart with increasing intensity. By means of letters from his father Leopold, his sister "Nannerl", himself and reports from his physicians and contemporaries, we would like to create a medical pathography. The rumour that Mozart was poisoned appeared soon after his early death at the age of 35 on December 5th 1791, and was kept up persistently. Accused were the physician van Swieten, Mozart's freemason's loge and the royal band master Salieri. Mozart, however, died due to chronic kidney disease and ultimately due to uraemia. Once the renal damage has reached a certain point, a minimum of additional stress leads to decompensation. This catastrophe occurs typically within the fourth decade of life. When listening to Mozart's music, we should remember that this apparently happy person was actually a premature adult robbed of his childhood, whose short life was an endless chain of indisposition, over fatigue, misery, concern and illness.