It took place in Gianyar regency, east of the island's cultural centre Ubud, after days of elaborate rituals. Traditional Hindu beliefs dictate that cremation will take the deceased to the after-life or reincarnation.
Mass cremations are common in Bali, where Hindu beliefs remain strong despite the island's transformation into a tourist mecca, and are held for poor families who cannot afford the ritual-heavy ceremonies alone.
Some of the people cremated on Monday had died up to five years ago.
"Cremation is an obligation for all Hindus so our spirits can be returned to nature," said Jero Mangku Sangging, the Hindu cleric leading the ceremony.
Fifteen families had paid for sarcophaguses carved in the shape of bulls – an animal that is sacred in Hinduism – to adorn the corpses.