During both his service and retired life, Khanbahadur Ahsanullah relentlessly tried his hand on literature and creative writings. He wrote many books on Education, literature, History, Biography, Philosophy, Religion etc.
He is the renowned author of 81 books. All of his Books have been complied in 12 volumes. The name of the compilation of his entire writings is"Khanbahadur Ahsanullah Rachanabali" (Volume 01 to 12), edited by Gholam Moyenuddin PhD, a well known litterateur and the former Director of Bangla Academy, Dhaka. Some of his outstanding publications included: Teachers' Manual (1952),Bangabhasha-O-Musalman Shahitya or Bengali language and Muslim literature (1918), History of the Muslim World (1931), Islam-O-Aadarsha Mahapurush or Islam and the ideal great man (1926), Tariqat Shiksha or learning the rules of spiritual attainment (1940), Shikshakhetre Bongio Mussalman or Muslims of Bengal in education (1931), Quran-O-Hadiser Aadeshaboli or the instructions of the holy Quran and Hadis (1931), Sufi(1947), Shristitatta or the origins of creation (1949), Islamer Mahaty Shiksha or the invaluable teachings of Islam (1949), Mahapurushder Amiyobani or the eternal messages of the great men (1950), Islamer Bani-O- Paramhangsher Ukti or the message of Islam and the sayings of Supreme Lord (1956) and Bibhinna Dharmer Upadeshaboli or the preachings of various religions (1965), etc.
The entire gamut of Khanbahadur Ahsanullah's literary thoughts originated from his deep feelings for his country, his language and his desire to do good for the human kind.
He had declared in unequivocal terms: "Social welfare should ideally be the aim of literature." He also said: "A nation which does not have its own literature, does not have self-esteem. The development of such a nation will always be a forlorn prospect. If one is to introduce oneself as a true Muslim and an equal to the rest of the world, then one has to uphold one's mothertongue with a nationalistic fervour. For restoring the very existence of the nation, the development of the Bengali language is a must."
Aiming at social welfare, national development and refinement of the individualistic characteristics of people, Khanbahadur Ahsanullah published a number of autobiographical books on great men. These included, the life of Prophet Mohammed (SM), life-sketches of a number of Sufi leaders, the lives of heads of states and a host of other historical personalities.
Along with reflecting on the instructions of Islam, he presented in his writings, the inherent loftiness and the very essence of such religious creeds which made them so unique. This trend can be well observed in the books like Sufi, Shristitatta, Islamer Mahati Shiksha and Tariqat Shiksha. He believed, "The educated people of the time has keen interest for the deep mysteries of Islam. But the stringent rules of the shariah (the traditions) refrained them from delving into such mysteries. Few people, however, could understand that by piercing the hard rules of the shariah, they could find a passage into the world of unknown knowledge and bliss."
The very skill of his writing and the novelty in the presentation of the subject-matters which had an unmistakable individualistic touch, transcended them from the temporal to the eternal, eventually earning them the honour of creative literature. By involving himself with the activities of various literary organisations, he also made literary endeavours and practice easy for others.