Background and Objective: This study aimed to verify the validity of a questionnaire that surveys confidence in sports among athletes in combat sports. The questionnaire addresses the concepts of persistence, calmness, hesitation, and physical prime. Material and Methods: Purposeful sampling using non-probability sampling was conducted in 367 players participating in university- and business-level athletics in the Republic of Korea. The data were analyzed using a multi-group confirmatory factor analysis, and a second confirmatory factor analysis with linear structural relations (LISREL) version 8.5. Concept reliability and average variance extracted (AVE) values were calculated using Excel 2010 (Microsoft Corporation, Redmond, WA, USA). Two-way (2×2) randomized group (RG) analysis of variance (ANOVA) was conducted using the SPSS 18.0 program (IBM Corp., Armonk, NY, USA). Results: We proved that the sub-factors measured by the survey questions were relatively exact regarding self-confidence in combat-sport athletes. The questions relating to self-confidence in sports could be applied to both male and female athletes alike. The scores of the male athletes were higher than female athletes in factors such as fighting spirit, calmness, and performing under pressure. The scores of the national athletes were higher than those of the non-national athletes with respect to the body preparation factor. Conclusion: These results suggest that the competitive sports questionnaire developed in a previous study could be utilized without difficulty in a confidence-related study of competitive sports athletes. The questionnaire is particularly effective in evaluating the confidence level of athletes.