The 47-year-old woman was found to have had an alcohol level of 0.073 mg per liter of breath as she was riding her bicycle in a village in Yen Chau District of Son La Province on Wednesday.
She was stopped by traffic police who were on duty at a checkpoint to test if people were driving under the influence.
She told the police that her family makes wine for a living and therefore she usually tastes the product. She also said that she thought she would not get into trouble if she was riding a bicycle.
Yen Chau police said the case is the first ever in the district when a cyclist was fined for DUI. In accordance with Vietnamese law, anyone driving with alcohol present in their body faces either a fine or criminal charges.
Under current regulations, alcohol concentration of more than 80mg/100 ml of blood or 0.4mg/l of breath attracts the highest fines of VND30-VND40 million ($1,293-$1,724). Drunk driving only results in criminal prosecution when it causes accidents or other consequences.