Scottish government minister Aileen Campbell is to step down at the next Holyrood election to spend more time with her family.
Ms Campbell, who has two sons aged five and nine, said she hoped to achieve “a better work-life balance”.
The communities secretary said her job had been “demanding in terms of pressure and time”.
Her announcement came after fellow SNP MSP Gail Ross revealed she was quitting to watch her son grow up.
Ms Campbell has been an MSP since 2007 and was previously minister for children and young people and minister for public health and sport.
She was the first member of the government to take maternity leave.
The Clydesdale MSP said in a statement: “My husband and I are very fortunate – we have managed to find ways for me to do my job and have a family at the same time.
“But there is no getting away from the fact that the job – while immensely rewarding – is demanding in terms of pressure and time.
“I hope in future I can spend a little more time with my boys at home.
“So, after much consideration, now feels like a good time to prepare myself for taking a step back from frontline party politics and government.”
She added that she would “work tirelessly for my constituents” until next year’s election, and that she would continue working in the cabinet “for as long as the first minister wants me to”.
Ms Campbell is the latest in a series of senior SNP figures to announce they will not seek re-election to Holyrood.
Earlier this month, 66-year-old Michael Russell, who represents Argyll and Bute, said it may be time for someone younger to represent the constituency.
It was also announced that Stewart Stevenson, who represents Banffshire and Buchan Coast for the SNP, will leave parliament at the election.
He is 74 and has been an SNP activist since 1961.