After working as a staff artist for All India Radio, Mamoon joined the Indian Police Service in 1977. He served in senior positions in Karnataka including as Inspector General. Mamoon served as the Chairman of the Karnataka Urdu Academy between 2008 and 2010.
He was removed in controversial circumstances in 2010 for functioning in an "arrogant manner".
High School Shivaprakash, Dean, School of Arts and Aesthetics, Jawaharlal Nehru University resigned from the Karnataka Sahitya Academy in protest of government interference in an autonomous body.