A career civil servant, he served as the principal secretary to Prime Minister Khaleda Zia until 2006.

[6][failed verification] In October 2006, Siddiqui was terminated from his position as the principal secretary of Prime Minister Khaleda Zia after the caretaker government assumed power.

[9] Siddiqui coined the term "cocktail ideology" to characterise the cultural profile of the Bangladeshi people in the 21st century.

Women and middle-aged men are, in general, the bearers of tradition and religious orthodoxy, while the younger generation tends to carry the flag for "decadent modernity".

Kamal Siddiqui has carried out this research in association with Sayeda Rowshan Qadir, Sitara Alamgir and Sayeedul Huq.