The objective of this cross-sectional study (whose baseline data were drawn from a longitudinal population study) was to determine if one-leg standing balance might be a useful marker of functional status in elderly persons independently living in an urban community (N = 512, mean age 73 +/- 7.0, 71.4% women). One-leg standing balance (ascertained by the Tinetti test) and functional status were obtained from a baseline gerontological assessment and follow-up questionnaires. Correlations were tested between one-leg balance and physical health and functional measurements. One-leg standing balance (OLSB) was abnormal in 24.7% of the population. At least one incapacity in instrumental activities of daily living (IADL) was found in 60.6% of those with OLSB abnormality, vs 45.5% in those with OLSB "adaptive" (borderline abnormal), and 33.3% in those with normal one-leg standing balance (p < 0.0001). Multivariate analysis showed 3 independent factors related to one-leg balance abnormality: age > 71 years (OR = 5.11, CI = 1.99-13.10); IADL deficit requiring help with transportation (OR = 3.61; CI = 1.15-11.40); and "poor" health status on the Iowa Self-Assessment Inventory (OR = 2.67, CI = 1.35-5.27). We conclude that one-leg standing balance may be a simple, predictive and inexpensive marker helpful in screening for low functional level and frailty in clinical practice.