The Art Gallery is located just opposite to the main historical gallery. The architectural style of this building represents typical features in many respects. The building is named as 'Juddha Jatiya Kalashala' after the name od then Rana Prime Minister Juddha Shumsher who had built the building with personal spending in 1999-2000 B.S. This building was the first building constructed for the museum purpose. In the narrative panels of the main entrance, there are beautiful images which reflect the events of nativity of Buddha as explained in the Buddhist jatak literatures. On the upper part of the entrance, there are images depicting the event of samundramanthan which means churning the ocean based on the Hindu mythological story. As the building was designed for a museum, the main entrance appears to have been a rough copy of torana of Sanchi stupa in India from first century B.C.

This building also provides numerous galleries for the exhibition of various Nepalese art forms in stone, terracotta, bronze, wood and painting.