The objective of this study was to explore characteristics of breathing pattern and anxiety levels of athletes involved in women's rhythmic gymnastics. We tested 13 college level female rhythmic gymnasts (GG) from the same team, and compared their results with those of 26 non-athlete medical students (RG). Subjects were tested by a CO(2) rebreathing method using a gas mixture of 5% CO(2) and 95% O(2). The trait and state anxiety levels of the subjects were tested using the Spielberger's trait and state anxiety inventory (STAI). GG was significantly higher in both trait and state anxiety levels and, in comparison with RG, they also exhibited significantly less variance in the % contribution of change in frequency to the overall increase in minute ventilation during CO(2) rebreathing when compared to RG. Furthermore, there was a positive correlation between both trait and state anxiety and % contribution of frequency change in the RG.