Falling related injuries are associated with morbidity and mortality among older persons. An accurate and comparable assessment of postural sway may offer a method for detecting those at risk for falling. Our purpose was to assess the validity and repeatability of an inclinometric method in assessing postural sway during quiet standing. To assess repeatability, 51 elderly women (aged 72 to 74 years) were measured twice by the same tester. To assess validity, postural sway in 29 elderly subjects (aged 69 to 86 years) was assessed using simultaneously the inclinometric and a force platform method. The test-retest reliability correlation of the inclinometric method was high for sway path length (coefficient of determination r(2) = 0.683), and moderate for sway area (r(2) = 0.500) and the analysis revealed no sign of bias. The correlation was moderate between the values of the inclinometric sway path length and those of the force platform for antero-posterior (r(2) = 0.466), lateral (r(2) = 0.694) and combined lateral and antero-posterior (r(2) = 0.623) directional sway movements. The inclinometric method offers an accurate and repeatable method for assessing postural sway and may be a feasible method to be used in the risk stratification of falling.