The Union for Transport Workers (NBRU) has called upon Minister of Transport, Shane Ross to establish transport police.
The request comes as anti-social behaviour and violence have risen on trains over the last two years.
Irish rail recorded 1,000 incidents during that period of time.
The real figure, however, is expected to be much higher.
The extent of the problem was unveiled through documents obtained by the RTÉ's This Week programme.
The records showed reports of aggressive behaviour, criminal damage, fighting and attacks against staff, according to the programme.
The National Bus and Rail Workers Union believes the official record doesn't reflect the number of cases actually occurring.
Dermot O'Leary, NBRU chief, said he has written to the Minister for Transport, in relation to the problem.
He has requested the establishment of dedicated transport police, based on the model used in the UK.
"Some of the incidents that are happening these days, unfortunately, are not being reported.
The underlying point is that there is a lot of anti-social behaviour and a lot of assaults on staff members," said Mr O'Leary.
Irish Rail did confirm that since the start of last year, over 1,000 incidents of anti-social behaviour were logged on trains.
This includes aggressive behaviour, fighting, criminal damage, and attacks on staff.
Barry Kenny, a spokesperson from the company said in response to the rise, they have increased security.
"We have 45.5 million passenger journeys a year so obviously the vast majority of people travel without incidents.
"We have increased our security resources to help deal with anti-social behaviour with 21 percent more now than two years ago," said Mr Kenny.