Police say they were dispatched to the scene at Blackstone and McKinley just after noon Tuesday.
Investigators say the woman was hit by an Amtrak train heading north.
When they arrived police saw that she was conscious and talking to emergency personnel.
Police say the woman was rushed to Community Regional Medical Center for treatment of possible internal injuries.
They are still trying to determine how she ended up on the tracks.
"We don't know what her intentions were, whether she put herself on the path of the train deliberately or if this was an accident," Lt. Burke Farrah of the Fresno Police Department said.
Investigators say the woman was possibly listening to music with headphones and did not hear the approaching train, despite several long and loud blasts from the horn.
The train was delayed for approximately one hour. No passengers were injured.