Shaymanonda Das was preparing for morning prayers at a temple in the south-western district of Jhenaidah when he was attacked.
Police said he was hacked on the neck several times with machetes.
More than 40 people have been killed in attacks blamed on Islamist militants in Bangladesh since February 2013.
That includes secular bloggers, academics, gay rights activists and members of religious minorities.
Police said the motive behind the latest attack was not clear.
But local police station chief inspector Hasan Hafizur Rahman told AFP news agency "the pattern of the killing is similar" to ones carried out by local Islamist militants.
Last month, a 70-year-old Hindu priest was hacked to death in a rice paddy fieldin the same district as Friday's attack.
The government says it has launched a drive against militants by arresting thousands of people.
Some of the killings have been claimed by so-called Islamic State or al-Qaeda linked groups.
However, the government has disputed these claims, and says IS does not have a presence in the country.
Instead, government members have blamed opposition parties and local Islamist groups. Bangladesh's home minister has suggested an Israeli link to the killings, describing an "international conspiracy" against Bangladesh.
Both the opposition and the Israeli government have denied any involvement - and Israel described the accusations as "utter drivel".
This week, Bangladeshi police charged seven people, including an opposition politician, over the murder of an Italian aid worker who was shot dead in Dhaka in late September.