Members of the Irish Deaf Society gathered outside Leinster House to call on the Government for the legal recognition of Irish Sign Language (ISL).
The chairman of the society, Dr John Bosco Conama, described ISL as the third indigenous language of Ireland and the first and natural language of many deaf people.
Legal recognition would oblige the State to provide and pay for interpreters if required when deaf people are using State services.
The society said the failure to recognise Irish Sign Language places the health and well-being of deaf people at risk, as they often struggle to avail of vital health and educational services.
However, the Department of Justice said tonight there are no plans to recognise it as the third official language.
The appeal came during International Week of the Deaf.