Bindusara was born to Chandragupta, the founder of the Mauryan Empire. This is attested by several sources, including the various Puranas and the Mahavamsa. The Dipavamsa, on the other hand, names Bindusara as the son of the king Shushunaga. The prose version of Ashokavadana states that Bindusara was the son of Nanda, and a 10th-generation descendant of Bimbisara. Like Dipavamsa, it omits Chandragupta's name altogether. The metrical version of Ashokavadana contains a similar genealogy with some variations.
Chandragupta had a marriage alliance with the Seleucids, which has led to speculation that Bindusara's mother might have been Greek or Macedonian. However, there is no evidence of this. According to the 12th century Jain Writer Hemachandra's Parishishta-Parvan, the name of Bindusara's mother was Durdhara.
The 16th century Tibetan Buddhist author Taranatha states that Chanakya, one of Bindusara's "great lords", destroyed the nobles and kings of 16 towns and made him master of all the territory between the western and the eastern sea (Arabian Sea and the Bay of Bengal). According to some historians, this implies conquest of Deccan by Bindusara, while others believe that this only refers to suppression of revolts.