VICTORIA'S Transport Minister Lynne Kosky has resigned from the ministry and state parliament because of significant health problems within her family.

Ms Kosky announced her resignation - with a state election set for November - at a press conference at 11am today in Melbourne.

She said when she told Premier John Brumby he was not completely surprised.

He told her that family comes first.

Ms Kosky stands down from portfolios in public transport and the arts and her position as a member of parliament after first being elected in 1996 in the seat of Altona, in Melbourne's west, where she grew up.

Ms Kosky said she had no regrets.

When questioned about the troubled myki ticketing system that is late and over budget, she said that there is always work to be done in public transport.

But she had overseen new projects and reform of the public transport system.

"I don't have any regrets, I have a fantastic portfolio and was able to achieve an incredible amount along with other people," she said.

"The time is right for me because of issues within my family to say goodbye to this part of my public life."

Mr Brumby joined the press conference 20 minutes after it started to give support to Ms Kosky whose voice at times was quivering and her eyes were welling up.

Putting his arm around her, he told reporters that his transport minister had made the right decision to step aside.

"I put to her in this position you must always put your family first and not look back in five or 10 years time and say I should have done it at the time and I didn't," Mr Brumby said.

"You only get one chance to get it right.

"It was the right decision and a decision I support fully."

Ms Kosky, who is married with two children, lives in the western suburbs.

A biography on a Labor website describes her ambition in public life to leave a positive legacy "to her local community in Altona and the west, to the state and the nation".