Prime Minister Enda Kenny easily prevailed as he sought all-party endorsement of his government's Protection of Life During Pregnancy Bill.
Ireland, almost uniquely in Europe, officially bans abortion in all circumstances.
But the Supreme Court in 1992 ruled that terminations should be legal if doctors deem one essential to safeguard the life of the woman, including from her own suicide threats.
Today's 138-24 vote backing the bill is the first of several tests. It faces final passage next week.