The incident took place in Lodhipur village when four family members came in contact with a live wire, police said.
They were taken to the Patna Medical College and Hospital (PMCH) where they died during treatment, they said.
The victims were identified as Parmanand Chandra (34), his wife Sita Devi (25), daughter Komal kumari (12) and son Neeraj Kumar (8}, police said, adding the bodies have been sent for post-mortem.