Session Judge of Gomati district Gautam Debnath awarded death sentence to Arjun Biswas (43) in a packed court room yesterday.
A resident of Sukanta Palli, Arjun killed his father Niranjan Biswas, mother Shobha and wife Kana at his residence.
The only survivor of his family was his five-year-old son who saved his life by hiding himself.
Poverty and family dispute were the causes for the thiple murder, according to the prosecution.
Arjun had fled from his house after the murders, but was arrested from another village of the district later.
Altogether 38 persons were witness in the case.