His first story Atasi Mami appeared in Bichitra in 1928 when he was only 20 years old. This was followed by Neki and Byathaar Puja. These stories established him as a major craftsman of this genre. Encouraged by this, he wrote his first novel Dibaaraatrir Kavya. Though written in 1929, it was not published until 1934. Within a span of 28 years, he wrote some 260 short stories and 39 novels. Some of his well-known works include Padmanadir Majhi, Putulnacher Itikatha, Jibaner Jotilota, Janani, Dibaaraatrir Kavya, Pragoitihasik, Atasi Mami, Sarisrip, Aaj Kaal Porshur Galpa, etc. He has been widely translated into many Indian and European languages.

With the other two famous Bandyopadhyays viz., Tarashankar and Bibhutibhushan, Manik forms the famous triad of the Bengali literature. Manik's voice is distinctly his, to quote: "[Manik] offers in his stories a penetrating insight into the changing times that saw the disintegration of colonial rule in India, in a setting of famine, communal riots and peasant uprisings. With his uncompromising commitment to realism, he studies an urban middle class losing its older values in its struggle to survive, and rural masses driven by ruthless exploitation and deprivation to virtual marginalization and dehumanization. While he never loses sight of the socio-economic pressures at work, he concentrates on how human relationships are affected and only too often distorted in the process, and how rebellion grows." (from the book-jacket of Selected Stories).