The 32-year-old 'Mary Kom' star is currently shooting for the period romance, which also stars Ranveer Singh and Deepika Padukone.
The film is based on the love story between Maratha Peshwa Baji Rao I (Ranveer) and his second wife Mastani (Deepika).
Priyanka plays Kashibai, the first wife of Baji Rao. The actress took to Twitter to share her experience of filming the movie.
"Didn't even realise how tired I was till I touched my bed. 'Bajirao Mastani' is so intense that I'm depleted! Kashi is one of my hardest parts!" she posted on her Twitter page.