The man, was said to have been screaming before he plummeted to his death at about 9.30am from the 200ft-high building and landed on the pavement.
It remains unclear whether the incident was a suicide or a tragic accident.
“ [The] poor guy he was screaming before he fell. I honestly thought it was some idiot mucking about till saw him fall.”
A man who was at the scene said: “Just the westbound traffic was stopped but trams going east had to stop as well because trams weren’t getting along the West End.
“It looked like the man fell in the Princes street direction from the monument because the police and paramedics were by the fence.
“There wasn’t much commotion or a lot of traffic being held up and people were just walking past normally.”
Edinburgh City Council tweeted: “Please be aware that Princes Street and the east side of the Gardens are currently closed while emergency services attend an incident.”
In 2013 a man died after jumping from the monument
landing just yards away from Christmas shoppers on Princes Street.
The man jumped from the west side of the landmark narrowly avoiding passers-by on the busy thoroughfare, in full view of nearby ice-skaters.
The Scott Monument tower is 61.11m (approx 200ft) tall and has a series of viewing platforms reached by a series of narrow spiral staircases.
Construction was completed in autumn of 1844 and the Victorian Gothic monument was dedicated to Victorian write Sir Walter Scott.