Datuk Zaiton is a Fellow and Council Member of the Association of Chartered Certified Accountants (ACCA), United Kingdom, member of the International Federation of Accountants (IFAC) Professional Accountants in Business (PAIB) Committee, a member of the Malaysian Institute of Accountants and the Malaysian Institute of Certified Public Accountants.

She started her career in PriceWaterhouse after which she joined Bank Pembangunan as a Project Officer. She then joined Maybank where she spent 12 years in various senior positions including heading Treasury, International Operations, Branch Operations and Group Strategic Planning. She left Maybank to set up Malaysian Rating Corporation Bhd (MARC) in 1996 and was its President / Executive Director until 2004. She established the Malaysia Professional Accountancy Centre (MyPAC) in 2015 and is currently its Chief Executive Officer.

Datuk Zaiton has extensive experience as an independent director. She was the Chairman of the Group Governance & Audit Committee of Sime Darby Berhad (before the pure play corporate restructuring), she is now the Governance & Audit Committee Chairman of Sime Darby Plantation Berhad. She is currently the Chairman of Bank Pembangunan Malaysia Berhad. She had been on the board of Bank Islam Malaysia Berhad since the year 2006 and had been chairing both the Audit & Examination Committee as well as the Board Risk Committee.

Datuk Zaiton was appointed Chairman of the Private Pension Administrator Malaysia by the Securities Commission Malaysia in 2012 to develop the Private Retirement Schemes for the country.