The Cystic Fibrosis Association of Ireland has said there are five CF patients waiting for an inpatient room in St Vincent's University Hospital in Dublin.
The association said this is unacceptable and is jeopardising the health of patients.
It said the hospital signed an agreement in July with the association that up to 34 beds would be provided when the new wing of the hospital opened in August.
The hospital said it is happy to participate in a review.
Philip Watt, Chief Executive of the CFAI said those waiting for admission are anxious and that at least one general ward is lying idle in the hospital.
There is also space in the old private hospital, he said.
Mr Watt said there are 27 inpatient rooms occupied by CF patients and five on the waiting list.
Up to seven patients have been waiting for a room over the past week, Mr Watt said.
The hospital said it received a letter from the association this morning asking for a review of facilities for CF patients and the hospital confirmed it is happy to participate in such a review.
In a statement, the hospital said it will continue to prioritise CF patients for admission based on their clinical need.
Cystic fibrosis patient and campaigner Orla Tinsley said the agreement between the CFAI and St Vincent's Hospital has to be renegotiated as it is not working.
She said the HSE also had a responsibility to ensure patients get the services promised.
Ms Tinsley, who was at St Vincent's Hospital this afternoon, said most CF patients who were waiting for a bed had decided to go home rather than spend time in other parts of the hospital and risk picking up infections.