A 58-year-old man suffered serious head injuries after allegedly being pushed down the stairs following an argument at Edinburgh Haymarket just before 10pm on Thursday night.
Police said a 35-year-old man had been charged with attempted murder and assaulting another 32-year-old man, who suffered facial injuries.
Detective inspector Brian McAleese, from British Transport Police, said: “We believe a verbal altercation took place between three men on the stairs between platform two and three, which resulted in one of the men being pushed down the stairs and another assaulted.
“Thankfully officers were quickly on scene and a 35-year-old man was arrested.
“I’d now urge anyone who may have witnessed the incident or the events leading up to it to get in touch with us as soon as possible to assist with our enquiries”.