Yaksa reliefs in Bharhut, Sunga period.

The Sunga dynasty (185–73 BCE) was established in 185 BCE, about 50 years after Ashoka's death. After assassinating King Brhadrata (last of the Mauryan rulers), military commander-in-chief Pusyamitra Sunga took the throne. Buddhist religious scriptures such as the Ashokavadana allege that Pusyamitra (an orthodox Brahmin) was hostile towards Buddhists and persecuted the Buddhist faith. Buddhists wrote that he "destroyed monasteries and killed Monks": 84,000 Buddhist stupas which had been built by Ashoka were "destroyed" (R. Thaper), and 100 gold coins were offered for the head of each Buddhist monk. In addition, Buddhist sources allege that a large number of Buddhist monasteries (viharas) were converted to Hindu temples, in such places as Nalanda, Bodhgaya, Sarnath, or Mathura.

Following Ashoka’s sponsorship of Buddhism, it is possible that Buddhist institutions fell on harder times under the Sungas but no evidence of active persecution has been noted. Etienne Lamotte observes: "To judge from the documents, Pushyamitra must be acquitted through lack of proof". Another eminent historian, Romila Thapar, points to archaeological evidence that "suggests the contrary [to the claim that Pusyamitra was a fanatical anti-Buddhist]" and never actually destroyed 84,000 stupas as claimed by Buddhist works. Thapar stresses that Buddhist accounts are probably hyperbolic renditions of Pusyamitra's attack of the Mauryas, and merely reflect the frustration of the Buddhist religious figures to the decline in the importance of their religion by the Sungas.

During the period, Buddhist monks deserted the Ganges valley, following either the Northern road (Uttarapatha) or the Southern road (Daksinapatha). Conversely, Buddhist artistic creation stopped in the old Magadha area, to reposition itself either in Northwest area of Gandhara and Mathura, or in the Southeast around Amaravati. Some artistic activity also occurred in central India, as in Bharhut, to which the Sungas may or may not have contributed.