The court ruled that a County Registrar was not entitled to exclude Joan Clarke, from Loughrea, Galway, from jury service.
However, the judgment does not clear the way for deaf people to serve on a jury.
Mr Justice O'Keefe said the presence of a sign language interpreter in a jury room would breach confidentiality, which is an integral part of trial by jury.
Lawyers for the Free Legal Advice Centres who took the case on Ms Clarke's behalf said they will return to court next week to pursue other aspects of the case.
