Plaid Cymru's chair, Helen Mary Jones says she will not seek re-election for the post during the party's conference in October.
She told ITV Cymru Wales that it was an opportunity for her to take a break from politics stating the party is "in a strong position" under the leadership of Leanne Wood.
In a letter to members she said: "The last two years have been very exciting for Plaid. Under our new chief executive we've modernised our organisation and campaigning, after a wide consultation through the 'Moving Forward' process. We have a new constitution in place. We have elected our new Leader, and we have just won stunning election victories in Ynys Mon and in Penyrheol, Caerphilly.
"I have been really proud to play my part as national chair in supporting all those who have worked so hard to make all of this possible. I have decided not to stand for re election when my term of office comes to an end at conference as I need to concentrate on my career and my family for a while."
The ex-Llanelli AM would not be drawn on whether she'll make a bid for her old seat at the 2016 Assembly Elections, though she did rule out standing as a candidate at the next UK General Election.