Objectives. This study investigated associations between frailty and functional disability in elder suburban Vietnamese. Method. Cross-sectional analysis was carried out on 251 participants aged 80 and over in Soc Son district. We used the Instrumental Activities of Daily Living (IADL) scale including 8 items, and functional disability was defined as ≥3 IADL impairment. We defined frail as ≥3 out of 5 frailty components including weight loss > 5 % , weak grip, exhaustion, low walking speed, and low physical activity. Results. Of 251 participants with a mean age of 84.6, 11.2% was classified as frail and 64.5% had ≥3 IADLs. Among the frailty components, low walking speed and low physical activity were significantly associated with increased odds of having ≥3 IADLs: ORs (95% CI) were 4.2 (2.3-7.9) and 3.7 (1.7-8.2). Conclusion. Frailty is associated with the higher likelihood of having functional disability. Further longitudinal studies are needed to examine the causal this relationship.