The six unarmed observers will join a United Nations mission, whose role it is to oversee a cessation of violence “in all its forms by all parties”.
The head of UN peacekeeping, Herve Ladsous, said the 24 monitors already in Syria had helped, simply by their presence, to reduce some of the worst mayhem in the country.
He accused the Syrian regime and the rebels of violating a ceasefire accord.
But he expected that the full contingent would be in place there by the end of the month.
Defence Minister Alan Shatter said participation by the Defence Forces in the supervision mission would, once again, reaffirm Ireland’s continued support for the UN.