The aim of the study was to provide evidence for the validity and reliability of the Physical Activity Affect Scale (PAAS; Lox, Jackson, Tuholski, Wasley, & Treasure, 2000) as a measure of exercise induced affect for adults with brain injuries. The PAAS is a 12-item measure of feeling states based on Russell's (1980) conceptualization of affect. A confirmatory factor analysis was conducted on data from 193 participants with brain injuries who completed the PAAS following a single bout of exercise. Results identified four dimensions of affect (positive affect, negative affect, tranquility, and fatigue). Findings provide evidence for the validity and reliability of the PAAS as a measure of exercise induced affect for adults with brain injuries.Keyword(s): adapted physical activity, physical activity, research