The aim of this study was to construct and validate a questionnaire of self-confidence in sport competition in Chile. This was administered to a sample of 307 athletes of individual and team sports on regular competition with ages ranging between 11 and 35 years. Exploratory and confirmatory factor analyzes supported a unidimensional structure of selfconfidence in sport situation. The Internal consistency are adequate. Significant positive correlations were observed with self-confidence dimension of CSAI II and global results of general self-efficacy by Schwarzer y Baessler (1996) which showed appropriate values with the sport sample.