The purpose of this study was to investigate cognitive appraisal of menstruation and menstrual symptoms (MMS) by female athletes in the competitive sports context, and to examine the relationships among the women’s cognitive appraisal of MMS, their interpersonal stress experiences in that environment, and their sports competitive trait anxiety. Female college athletes (n=188) aged 18 to 23 years (m=19.81, sd=1.32) completed three questionnaires: one consisting of cognitive appraisal questions created for this study; another made up of interpersonal stressor questions which they were asked to answer while competing during MMS; and a third relating to the trait anxiety scale for sports (Hashimoto et al., 1986). Factor analysis revealed two cognitive appraisal themes, “threat” and “controllability”, related to both menstruation and menstrual symptoms. Analysis of covariance (ANCOVA) revealed that the athletes experienced social stress in the competitive environment during MMS, strongly recognized “threat”, and felt it was difficult to handle MMS. Multiple regression analysis revealed that the athletes who showed high levels of cognitive anxiety about losing tended to recognize MMS as a threat to their performance. The results suggest that cognitive appraisal of MMS by female athletes is associated with interpersonal stress and is influenced by sports competitive trait anxiety.