Around 80% work two to five hours after normal working hours to finish their jobs though only 43% are paid for it.
Only 4% of the 3,349 workers polled said they spend more than 10 hours a day with their family.
Most of those working overtime get less than VND1 million (US$46) a month, 32% get VND3-5 million (US$138-230), 8% get VND5-10 million (US$230-460), and 7%, more than VND10 million.
56% said they do not feel "uncomfortable" working overtime if they get benefits like advancement opportunities, payment, or time off in lieu.
In comparison to other countries in the region like Malaysia, Vietnamese workers seem to be addicted to working, the survey said.
Most Vietnamese said they do overtime to earn more money though 30% said they do it "spontaneously".
However, 44% said they are stressed and not happy to do "too much" overtime, and a full 80% are ready to move if it means a better work-life balance.