Worry is often defined as the cognitive component of anxiety and can take the form of relatively uncontrollable, unpleasant, negative intrusive thoughts (Borkovec, Shadick, & Hopkins, 1991). Given the potentially debilitating effects that high levels of cognitive anxiety or worry can have upon athletic performance (Burton, 1988), worry has been recognized as an important variable to study in sport (e.g., Gould, Horn, & Spreemann, 1983). Dunn (1999) recently examined the latent dimensionality of competitive worry in a sample of 178 male intercollegiate ice hockey players and observed that competitive worry could be structured around four possible dimensions: fear of performance failure, fear of negative social evaluation, fear of injury or physical danger, and fear of the unknown. The primary purpose of this study was to extend Dunn’s work by examining the dimensionality of competitive worry in another high contact sport. The second purpose was to examine the degree to which worry dispositions across the four proposed domains of worry predicted pre-competitive state anxiety (A-state). It was hypothesized that athletes who had high worry dispositions across the four worry domains would have higher cognitive and somatic A-state scores than athletes with lower worry dispositions across the four domains. A total of 174 male Canadian Football players (M age=18.24 years) completed a newly constructed self-report instrument, the Football Worry Scale (FWS), to measure athletes’ dispositional tendencies to experience competitive worry in football. A sub-sample of athletes (n=104) from three teams also completed the Competitive State Anxiety Inventory-2 (CSAI-2: Martens, Burton, Vealey, Bump, & Smith, 1990) 45 minutes prior to competition to measure pre-competitive A-state. Confirmatory factor analyses of FWS data supported the retention of four factors to reflect the latent dimensionality of competitive worry in Canadian Football. Two simultaneous multiple regression analyses were conducted to examine relationships between FWS and CSAI-2 subscales. For each analysis, either the CSAI-2 cognitive or somatic subscale was entered as the dependent variable, and the four FWS subscales entered as independent variables. The FWS subscales significantly predicted CSAI-2 cognitive A-state (F [4, 100]=17.284, p < .001, R²=.409) and somatic A-state (F [4, 100]=3.686, p < .01, R²=.128). Worry about situational uncertainties (i.e., fear of the unknown) was the strongest predictor of both cognitive and somatic A-state. Results reaffirm the need to treat competitive worry as a multidimensional construct, and highlight the role of situational uncertainty in the competitive sport anxiety process.Keyword(s): athletics/sports, coaching, performance