Subjective reports of physical activity are often biased due to recall and social desirability. Objective data is limited by what the device measures. The purpose of this study was to consider the feasibility, reliability and validity of the MotionWatch 8 among older adults in assisted living. A total of 249 residents were recruited from 26 assisted living facilities. Data collection included descriptive data, the Barthel Index, MotionWatch 8, and falls data. A repeated measure analysis, regression analysis and Multivariate Analysis of Covariance were done to test consistency of activity over three days, the relationship between the MotionWatch 8 and function, and differences among fallers and non-fallers. Participants were 86.86 (SD=7.0) years of age, mostly women 179(74%) and white (N=232, 96%). The study provided additional support for feasibility, reliability and validity of the MotionWatch 8. Advantages were comfort and wearability, simplicity of use and more accurate assessment of intensity of activity.