University Hospital Galway (UHG) is one of many hospitals highlighted by the Irish Cancer Society for what it calls "excessive" car parking fees.
The charity points to a cut in funding having serious knock-on effects for cancer services.
Irish Cancer Society CEO Averil Power said the exorbitant car parking charges are yet another hidden cost for cancer patients under financial pressure. She described the fees - in some cases up to €3.20 an hour - as a "tax on the sick".
"We see screening hasn't been expanded as planned and waiting times for cancer tests are longer than they should be with diagnoses and surgeries frequently delayed.
"The result is that people with cancer are paying the price with poor outcomes and quality of life. That's why we're calling on the Government to make changes and properly fund cancer services in next year's budget."
A survey by the society shows that in Co Dublin, there is no free parking or concessions for cancer patients at Beaumont Hospital, Mater Misericordiae University Hospital Dublin, Tallaght University Hospital or Connolly Hospital.
Full fees are charged at UHG Galway, Midland Regional Hospital Portlaoise, Our Lady of Lourdes Hospital in Drogheda, University Hospital Waterford and Mullingar Hospital in Co Westmeath.
The society said cuts in funding has seen cancer services plummet to almost €180m between 2017 and 2024.
Professor Michael Kerin is Director of the Cancer Programme for the west and northwest. He said there remains significant infrastructure and staffing challenges in cancer care services.
"I think the twin challenges really are infrastructure and staffing. We've moved to an eight-cancer centre model in Dublin and here in Galway we have a new radiation oncology building to deliver care locally.
"We've managed to get a cancer centre on the National Development Plan for the region of Connacht and Donegal and into the Midlands and Midwest for common services like Breastcheck and prostate. We're hoping to get that built in the short term.
"That needs to be delivered and I believe if we have appropriate infrastructure, we will then be able to provide optimal cancer care and that involves not having the cancer patient in competition with the emergency patient for care."
Professor Kerin was one of several cancer doctors and researchers who wrote an open letter to Taoiseach, Simon Harris, earlier this year regarding underfunding of the National Cancer Strategy.
"People with cancer in Ireland deserve the best possible chance of surviving the disease and enjoying a good quality of life afterwards. This will only be achieved through properly resourced cancer services, with protected pathways that are not disrupted by other pressures on the health service.
"We urge you to reverse the decision to provide no new recurrent funding to the National Cancer Control Programme in 2024 and to commit to sufficient ringfenced multi-annual funding to enable full delivery of the national cancer strategy 2017-2026."
