One problem in the optimization of athletic performance is that consistency in practice situations is not always carried over to competitive situations. There is an increase in irrelevant stimuli in competition which cannot always be gated out satisfactorily by the anxious athlete. We investigated the physiological responses to relevant and irrelevant stimuli of 48 elite female gymnasts differing in levels of anxiety and defensiveness. Cardiac responses were recorded to tone presentations and analyzed as a function of instructions, anxiety manipulation and group. The results suggest that phasic responses of high-anxious gymnasts were larger than those of low-anxious gymnasts. High-anxious gymnasts experience more difficulty in completely gating out the occurence of irrelevant stimuli than do low-anxious gymnasts. Finally, under anxiety-producing conditions, high levels of defensiveness and anxiety in combination appear to have a debilitating effect on the gymnast's ability to discontinue processing of irrelevant stimuli, while truly low-anxious subjects appear distracted from processing relevant stimuli. Further investigation of the interactions between levels of trait anxiety and anxiety-producing situations in a sport-specific domain appear warranted. The role of defensiveness in these interactions should also be investigated. © 1988.