Background Road traffic injury is a leading cause of death and disability in Vietnam, but information on the contributions of specific behavioural risk factors is limited.

Purpose To assess the blood alcohol concentration (BAC) of road traffic injured patients presenting at three provincial and central hospitals in the Socialist Republic of Viet Nam by age, sex and road user type.

Methods A descriptive cross sectional study measuring BAC in all consenting road traffic injured patients presenting at three hospitals between July 2009 and September 2010. All results were anonymous and summary information on key variables were sent to MOH and the WHO on a monthly basis.

Results Of 36 418 road traffic injured patients presenting to these hospitals during the study, BAC analysis was completed on 14 990 patients (41.2%), representing all patients 15 years of age and above, who consented to anonymous testing. BAC results ranged from zero to 0.589 g/dl blood, with a mean of 0.0441 g/dl. Of all patients tested, 56.8% had no detectable alcohol. Motorcycle riders were the most common patients represented in the tested sample (70.7%), with 27.8% having a BAC above the legal limit (0.05 g/dl). Car or other vehicle drivers represented 2.7% of the sample, with 63.4% tested having a BAC above zero (0 g/dl), the legal limit for these road users

Significance This preliminary study indicates that 29.1% of injured car drivers and motorcycle riders exceeded the legal BAC limit for operating a vehicle, suggestive that strengthening enforcement of drink–driving to be urgent national road safety priority.