The incident occured on the so-called 'green line' between the Pirámides and Acacias stations.
When the train stopped for 15 minutes at around 8.30am, a number of impatient passengers unblocked the train doors and began walking down the tracks.
"Service on the line was suspended as soon as the driver realised passengers had left the train," a spokesperson for Madrid Metro told The Local.
"It's obviously very dangerous. It's also strictly prohibited to leave the train unless Metro personnel tell passengers to do so," the spokesperson added.
Late last year, several hundred passsengers on Line 5 were stranded for over an hour and a half. One passenger required treatment after she had an anxiety attack.