A trainee nurse has saved a man from an oncoming train after he fell onto the tracks in Brisbane.

The 56-year-old man appeared disoriented when he stepped off the platform and fell one metre on to the tracks at Wooloowin station, in Brisbane's north, at 8.02am on Thursday.

The Doomben to Cleveland train was due to pull in to the station at 8.04am.

A trainee nurse who saw the man immediately ran to his aid, risking her own life by jumping on to the tracks.