Mark Waller will retire as chair of Ebos Group after the annual meeting on October 15.
Waller joined the company as chief financial officer in 1984 and became managing director in 1987, a position he held through to 2014.
During that period, he transformed the company from a small player in the healthcare market with annual revenue of about $8 million to the largest trans-Tasman healthcare and animal care operator with revenue of more than $6 billion.
He remained on the board, becoming chair in 2015.
Ebos shares are trading at $24.21, valuing the company at $3.9b, and have gained more than 16 per cent in the past 12 months.
The board has elected Liz Coutts, a director since 2003, to take over as chair.