Many athletes and spectators believe that experiencing and controlling psychological momentum is a critical component to achieving success in sport (Perreault, Vallerand, Montgomery, & Provencher, 1998; Stanimirovic & Hanrahan, 2004). Despite this, little is known regarding why some individuals perceive momentum differently than others. This study was designed to determine if optimistic thinking has a relationship with psychological momentum perceptions. Female Division I NCAA volleyball players (N = 68) completed the Life Orientation Test – Revised (Scheier, Carver, & Bridges, 1994), the Sport Attributional Style Scale - Short (Hanrahan & Grove, 1990b), and a psychological momentum survey. The results indicated that attributional style constructs intentionality and globality were significant predictors of psychological momentum perceptions. Also, participants had greater disagreement regarding the momentum value of early and late points in a set than those in between. Neither dispositional optimism nor sport-specific optimistic attributional style were correlated with psychological momentum perceptions. Future attempts to measure psychological momentum perceptions should consider a mixed methods approach along with more ecologically valid assessment protocols. / Department of Psychological Science