The surveillance video shows the woman - who was identified only as Candela - losing her balance and falling to what appears to be a sudden death.
WARNING: This video may be difficult to watch.
She fell under the moving train, but somehow survived. The woman was rescued by the train station's security and several doctors and only suffered minor injuries.
Candela reportedly told an Argentinian TV station she suffered a loss in blood pressure, causing her to faint.
She said she has no idea how she is still alive.