Dr Ajayi joined Nigerian Breweries Plc in 1989. In 1996 he became Star Brand Manager and in 1998, he proceeded on internationalization to Heineken International B.V, Amsterdam, where he served as Business Consultant until 2001.

He was appointed General Manager, Heineken Canarias in 2001. In 2004, he returned to Nigerian Breweries Plc as Head of Customer Service and was appointed Customer Service Director in April 2005.