Bank of Queensland chief executive and managing director Jon Sutton stepped down with the bank now scouting for a replacement.
Sutton resigned after three years on the job to focus on his long-term health following a heart operation earlier this year, the bank said.
Current chief operating officer Anthony Rose is taking over as interim chief executive as the bank conducts a global search for a replacement.
BOQ chair Roger Davis supported Sutton's decision to step down and Rose's ability to take over as the interim.
"We understand and respect Jon's decision to resign now, so as to focus on his health and be in great shape to return to corporate life when it makes sense for Jon and his family," Davis said.
"We thank Jon for his loyalty, dedication and significant contribution since he joined BOQ as our chief operating officer in 2012 before stepping up into the role of managing director and chief executive officer in 2015 and wish him all the best for the future."
Given Anthony's experience and knowledge of the business, the bank has no doubt it will be business as usual during the search period, he said.
Sutton said he looks forward to re-engaging with the banking industry in the future.
"After consulting with my family, I've made the decision to resign to focus on my long-term health. In February, I underwent emergency surgery for triple heart bypass. In the interest of stability, I felt it was important for me to return to lead the business throughout 2018, by the time is now right to look after my health and BOQ is understanding of that," Sutton said.
"Expanding and enhancing the banking services for Australian businesses and families has been my life for the past 25 years and I look forward to further engagement with the sector in the future."