Cork South West and Fine Gael TD Jim Daly has announced he will not contest the next general election and is to leave politics to spend more time with his family.
Mr Daly said in a video message that the decision was very difficult for him.
He has served as Minister of State for Mental Health and Older People for the past two years.
Deputy Daly said he has found it increasingly difficult to balance political life as a career politician with family life.
He lives in Clonakilty and said that spending three to five days a week in Dublin in his ministerial role had become unworkable.
Mr Daly has represented his west Cork constituency for 16 years.
He said he was proud of his record of delivery in infrastructure, on flood schemes, schools, roads and hospitals and in particular achievements made during his time at the Department of Health.
He said that he has learned that you cannot change the world, but that one of the greatest honours of his life has been to change someone's world during his political career.
Mr Daly thanked all his supporters and said it has been an extraordinary honour to fight several elections successfully and be a poll topper.
