The purpose of this study was to develop and psychometrically test the Activity Effort Scale among women aging with the affects of paralytic polio. On the basis of prior qualitative research, six items were generated. Two researchers with expertise in disability were consulted for examination of the items, which led to the addition of two more items to the scale. Next, a survey was sent to 500 women with a history of paralytic polio. Data from participants were subjected to psychometric testing: factor analysis, reliability testing, and correlation with existing measures. Useable surveys were returned by 299 women aged 49 to 75 years. Mean age of infection with polio was 7.6 years, and 54% had spinal polio. Principal component analysis of the 8-item scale resulted in one component with an eigenvalue above 1, explaining 74% of the variance. The Cronbach's alpha was .92. Correlations between variables supported content validity. Data suggest that the Activity Effort Scale is a valid and reliable tool consisting of one component measuring frequency of effort exerted beyond levels of discomfort, pain, and fatigue among women aging with paralytic polio.