Tasmanian Police Minister Jacquie Petrusma is resigning from state parliament for "personal and family reasons", Premier Jeremy Rockliff has announced.

Ms Petrusma, who also holds the fire and emergency management, prevention of family violence, and parks portfolios, has been in state parliament since 2010.

She is the fourth Tasmanian minister to quit Cabinet this year — following Sarah Courtney, Jane Howlett and former premier Peter Gutwein.

In a statement, Ms Petrusma said it had been a "challenging decision, but it is the right one for my family".

"Being a Minister and a Member of Parliament is an incredible honour and privilege, however, there is no denying that the time required impacts your family," she said.

"As a daughter, a mother, a grandmother, a wife, I need to now more than ever, spend more time with my family and provide extra support."

Ms Petrusma, who in 2018 revealed she was a victim-survivor, said "responding to and the prevention of family and sexual violence was one of the strongest motivations for me becoming an MP".

Mr Rockliff said Ms Petrusma informed him of her decision to end her 12-year political career yesterday, while she was still on leave.

"Jacquie is stepping down to spend more time with her family and I wish her the very, very best, and I thank her sincerely for her hard work and her dedication," Mr Rockliff said, fronting a press conference by himself.

The Premier deflected questions about government instability, instead saying it would be an "opportunity to refresh and bring new people into our parliamentary Liberal team".

Mr Rockliff said he had had no indication Ms Petrusma was intending to quit before yesterday.

"No, it was a surprise to me," he said.

"It is a tough gig, being a member of parliament … families wear the brunt of that sacrifice."

Mr Rockliff said Ms Petrusma had been "an absolute trooper" over the past 12 years.

"I'm sad to see Jac go, she's been fantastic to work with, fun to work with and she's demonstrated enormous dedication and commitment to her electorate of Franklin but also the ministerial portfolios that she has held over the course of the last eight years," he said.