The actors were accompanied by Bachchan's father, veteran Bollywood star Amitabh Bachchan, and his family as they visited the famous Kashi Vishwanath and Sankat Mochan temples in Varanasi and participated in the traditional Hindu prayer rituals.
Neither the Bachchan family nor Rai made any comments to the waiting media crowd.
Abhishek Bachchan and Aishwarya Rai are currently starring together in the Bollywood movie "Guru" and have appeared in several movies together, including "Dhoom 2" and "Umrao Jaan."
The visit to the temple was significant, because it marks the first time Rai has taken part in a Bachchan family-only event.
Bachchan and Rai were scheduled to leave for Agra, site of the fabled Taj Mahal, after the rituals.
Rai has served on the Cannes Film Festival jury and is featured in international ad campaigns for leading jewelry, cosmetic and cola companies.