The Irish Blood Transfusion Service (IBTS) says there is no delay in transgender donors giving blood.
It comes after a transgender woman waited for a year to have her details changed on the computer system.
The IBTS says the system has now been set up and tested to allow for transgender people to present as their preferred gender.
A new questionnaire has been added to take other factors like sexuality activity or haemoglobin levels into account.
Dr Stephen Field is the medical and scientific director at the IBTS.
"The gender of a person is important, in terms of how the components of the blood collected is actually used.
"If somebody, for example, is female initially and have been pregnant they may have made antibodies when they were pregnant which may have an affect when you give plasma products to a patient."
"With our change of gender on the computer system, we just need to ensure the right questions are asked of the donor when they present.
"It's not just a question of changing male to female.
"We certainly respect our donors and if they do change gender, we have to treat them without any discrimination or anything like that", he added.