Geissler started at Procter & Gamble in 1979 after having obtained an MBA (Diplom-Kaufmann) at the Albertus-Magnus University of Cologne. Prior to that he spent 2 years at the German Air Force.
At Procter & Gamble, Geissler worked in Product Management with increasing levels of responsibility. In 1991, he became General Manager of the acquired Cosmetics and Fragrances business. He has lived and worked in Germany/Frankfurt; Holland/Rotterdam, California/Santa Monica, Turkey/Istanbul (where he had responsibility for the business in Turkey and Caucasian and Central Asian Republics), Japan/Kobe (as President of the North East Asia business), Switzerland/Geneva where from 2004 to 2007 he led the Central & Eastern Europe, Middle East and Africa region. In 2007, he became Vice Chairman, Global Operations, based in Cincinnati/USA. He retired in January 2015.
Geissler is now Operating Partner at the Private Equity company Advent International, focusing on Consumer Goods and Retailing. He is a Member of the Supervisory Board of the Goodyear Tire Company and Philip Morris International, respectively. He has been on the Board of GS 1 Global, economiesuisse, and the World Business Council for Sustainable Development as well as a member of the Summit Committee of The Consumer Goods Forum. He is an Advisor to the Governor of the Hyogo Prefecture/Japan. He is a Visiting Professor of CELAP/Shanghai.