In the next year, he joined Chatra Nandalal Institution at Serampore and acted as the Headmaster of the school for seven months.

At the suggestion of Ramesh Chandra Dutta, the then Magistrate of Barisal, he established the Brojomohun School in the memory of his father, on 27 June 1884.

Ashwini Kumar Dutta was elected as a delegate to the second session of Indian National Congress, held at Kolkata in 1886.

That year he attended the third session of Indian National Congress in Chennai and spoke on the need for reforms in the Legislative Council.

He founded the Swadesh Bandhab Samiti to promote the consumption of indigenous products and boycott foreign goods.

In 1908, the government of the newly formed Eastern Bengal and Assam banned the Swadesh Bandhab Samiti 1908 and deported him to the United Provinces where he was interred at the Lucknow jail.

In 1921 at the Kolkata session of the Indian National Congress, he lends the non-violent Non-Cooperation Movement.