The rape of gangster Tommy's girlfriend Siobhan by IRA thug Git led to a flurry of calls to the Rape Crisis Centre as well as 17 complaints to Montrose.
The makers of the hit series had already warned that it would get darker and more violent as it sought to portray the violence of gangland crime.
RTE had warned viewers of its violent content before it was aired, and also linked viewers to a an Aertel page if they had been affected by the subject matter.
Ellen O'Malley Dunlop, CEO of the Dublin Rape Crisis Centre, said the rape scene in Love/Hate had brought back horrific memories for rape victims and led to a sharp spike in the number of calls to the centre.
"Love/Hate contacted us and said they would be putting up information on how to contact us, and that is good, but when they did refer to the helpline it was put up on Aertel and we would have preferred it on screen," Ms O'Malley Dunlop added.
"Some people don't have the wherewithal to access Aertel when they are that distressed," she commented, adding that they had also received calls from people who had never been assaulted but were distressed at what they had seen on RTE.
But the Rape Crisis Centre did not call on RTE to cut out graphic assaults altogether because of the need to reflect reality.
"What is important is that it mirrors what is happening right now in Irish society.
"The amount of sexual violence around the country has escalated considerably and people need to be aware that we are a national helpline, not just Dublin, and to pick up the phone," said Ms O'Malley Dunlop.
"What Love/Hate did was show an unsavoury and worrying side of Irish society."
RTE confirmed it had received nine emails and eight phonecalls complaining about Sunday's episode. The drama was watched by 650,000 viewers, with 970,000 tuning at some stage of the broadcast.
The station defended putting the Rape Crisis Centre number on Aertel, saying it remains visible for longer and can be accessed by people in their own time.
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