This study investigated how metacognitive beliefs in triathletes covary with state anxiety dimensions, prior to competition. It also examined how metacognitions relate to concentration, after controlling for state anxiety. Regression analyses revealed that specific metacognitive beliefs were differentially predictive of state anxiety dimensions and concentration. When accounting for the state anxiety variables in a hierarchical model predicting concentration, positive beliefs about worry, negative beliefs about worry, and cognitive anxiety remained as significant predictors. Metacognitive beliefs were also found to differ across time-to-event intervals. Overall, the results demonstrated that a metacognitive framework is a viable pathway for future sporting research.