Police, paramedics and fire crews attended and Westbourne Road was closed both ways outside the station after the incident at 7.22am.
British Transport Police (BTP) led the response, which has now been resolved, and a man has been taken to hospital with a leg injury.
A BTP spokesman: "Officers were called to Lancaster station at 7.22am this morning (January 14) following reports of a casualty who had fallen from height.
"Paramedics and the fire service also attended and a man has been taken to hospital with a leg injury."
A fire service spokesman added: "Three fire engines from Lancaster and Morecambe, the Aerial Ladder Platform (ALP) from Morecambe, Urban Search and Rescue from Chorley and the Rope Rescue Team from St Anne’s, attended an incident at Lancaster Railway Station.
"Upon arrival, crews found a casualty that had fallen down a 15ft embankment close to the railway lines.
"The casualty was lifted to safety using the Aerial Ladder Platform (ALP), a basket stretcher and a rope pack.
"Casualty was handed over to North West Ambulance Service. Fire crews were in attendance for around two hours and fifteen minutes."
The road closure, from Meeting House Lane to Station Road, caused long traffic queues outside the station and along the A6 during the morning rush hour.
The station was still accessible by car via St George's Quay, but tall vehicles had to wait until the road reopened due to the low bridge on the Quay.
TransPennine Express said it expected "severe delays to all services" until around 10.45am due to police "dealing with trespassers" on the railway between Lancaster and Preston.
British Transport Police have not confirmed whether the two incidents are linked.
North West Ambulance Service has been approached for an update on the casualty.