Cimino surprised political observers at Queen's Park and his hometown with a statement saying he was resigning as of today, citing "personal health wellness" and the well-being of his family.
He says it was difficult as a Sudbury city councillor to do his job and find time for his wife and two young daughters, but adds "the pendulum has swung too far to one side" in recent months.
Cimino also asks the media to respect the fact that he is returning to private life and that his written statement would be his "only comment on the tough decision" that he made to quit.
NDP Leader Andrea Horwath says it's with great sadness that she received Cimino's resignation and wished him the best of luck in his future endeavours.
Premier Kathleen Wynne will have six months to call a byelection in Sudbury to replace Cimino.
Also on HuffPost