Over 840 children who attended the emergency department of Temple Street Children's Hospital last year were discharged with no fixed address, typically into emergency accommodation - a 29% increase on the 2017 figure.
A quarter of the children were younger than one-year-old.
Lead Emergency Medicine Consultant at Temple Street Dr Ike Okafor said the number of children discharged with no fixed home address has been climbing steadily in recent years.
Speaking on RTÉ's Morning Ireland he said: "I remember five, six years ago when you would get the odd parent asking you to give them a letter, to support their housing because their child was asthmatic, and they feel their housing issues are playing a role in that.
"It goes from one a month, to two a month, to three a month. Now its gotten to the extent that we are actually alarmed, and its hard to alarm us because we work in the ED."
Dr Okafor also said that all the signs show that a lot of the injuries presenting are linked to a child's housing situation.
"We are seeing a lot of injuries, that are occurring in accommodations where it is hard to child proof. We see things like scalds and burns. we're seeing falls, which may well not have occurred, if they were housed properly."
Dr Okafor said children in emergency accommodation are also more vulnerable to infection.
"If you look at the number of cases that present, based on the population of children who are in emergency accommodation around Dublin, they represent at least twice the normal number of kids who don't live in emergency accommodation.
"There might be a reason for that aside form the fact that they are more prone to infection, such as a lack of GP access. But we feel their living conditions definitely put them at risk."
In a statement the hospital said research shows that homelessness influences every facet of a child's life from conception to young adulthood and the experience of homelessness inhibits the physical, emotional, cognitive, social, and behavioural development of children.
Head Medical Social Worker at Temple Street Anne Marie Jones said: "The situation is shameful. When these children leave our ED, they stay in temporary accommodation with cramped conditions and no appropriate cooking, washing or play facilities.
"This results in accidents or traumas that wouldn't normally happen if these families were housed in a family home."
The Taoiseach has accepted that living in emergency accommodation complicates conditions for children living with chronic diseases or injuries.
Responding to questions in the Dáil, Leo Varadkar said: "Roughly 50,000 children attend Temple Street every year, roughly 800 of whom last year were living in emergency accommodation."
Mr Varadkar said they attended the emergency department "for many reasons" such as chest infections, vomiting, high blood pressure, chronic conditions like asthma and epilepsy.
"Of course if they are living in emergency accommodation that complicates it and that is why we want to get them out of emergency accommodation," he said.
Mr Varadkar defended the Government's record on child protection and welfare, and said child poverty and child deprivation have fallen for the past four years "because of the improved economy and the social policies pursued by this Government".
He said the Government was "ramping up" the provision of social housing and figures to be published in the coming weeks will show the stock of social housing increased by 8,000 last year, including 4,000 new builds by local authorities.
Sinn Féin's Mary Lou McDonald, said it was "disgraceful" that children were discharged to emergency accommodation and it showed they are "not valued by the State."
She said: "Not alone are these children left without a home. The State sponsors a system in which they live in unsuitable cramped temporary accommodation, that is their reality".