The non-cooperation movement was a reaction to the oppressive policies of the British Indian government such as the Rowlatt Act and the Jallianwala Bagh massacre. A meeting of civilians held atJallianwala Bagh near theGolden TempleinAmritsarwas fired upon by soldiers under the command of Brigadier-GeneralDyer, killing and injuring thousands of protestors. The outcry generated by the massacre led to thousands of unrests and more deaths at the hands of the police. The massacre became the most infamous event of British rule in India.

Gandhi was horrified. He lost all faith in the goodness of the British government and declared that it would be a "sin" to cooperate with the "satanic" government.

Indian Muslims who had participated in theKhilafat movementto restore the status of the Caliph gave their support to the non-cooperation movement. In response to the Jallianwala Bagh Massacre and other violence in Punjab, the movement sought to secureSwaraj, independence for India. Gandhi promisedSwarajin one year if his Non-Cooperation programme was fully implemented. The other reason to start the non-cooperation movement was that Gandhi lost faith in constitutional methods and turned from cooperator of British rule to non-cooperator.

Other causes include economic hardships to the common man, which the nationalists attributed to the flow of Indian wealth to Britain, the ruin of Indian artisans due to British factory-made goods replacing handmade goods, and resentment with the British government over Indian soldiers dying inWorldwar while fighting as part of theBritish Army.