BackgroundVietnam’s aging population is growing rapidly, but its health workforce’s capacity to provide quality geriatric care is not clearly understood. We aimed to provide a cross-culturally relevant and validated instrument to assess evidence-based geriatric knowledge among healthcare providers in Vietnam.MethodsWe translated the Knowledge about Older Patients Quiz from English to Vietnamese using cross-cultural adaptation methods. We validated the translated version by evaluating its relevance to the Vietnamese context, as well as its semantic and technical equivalence. We fielded the translated instrument on a pilot sample of healthcare providers in Hanoi, Vietnam.ResultsThe Vietnamese Knowledge about Older Patients Quiz (VKOP-Q) had excellent content validity (S-CVI/Ave) and translation equivalence (TS-CVI/Ave) of 0.94 and 0.92, respectively. The average VKOP-Q score was 54.2% (95% CI: 52.5—55.8) and ranged from 33.3 to 73.3% among 110 healthcare providers in the pilot study. Healthcare providers in the pilot study had low scores on questions related to the physiopathology of geriatric conditions, communication techniques with sensory impaired older adults, and differentiating age related changes from abnormal changes or symptoms.ConclusionsThe VKOP-Q is a validated instrument to assess geriatric knowledge among healthcare providers in Vietnam. The level of geriatric knowledge among healthcare providers in the pilot study was unsatisfactory, which supports the need for further assessment of geriatric knowledge among a nationally representative sample of healthcare providers.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12877-023-03958-3.