Purpose. The purpose of this study is to investigate how professional self-concept and ego-resilience of nursing students affect their clinical competence. Methods. This study conducted a structured-questionnaire survey with 143 nursing students to look into their professional self-concept, ego-resilience and clinical competence. Results. According to the study result, professional self-concept scored 2.85 on average out of 4 points, ego-resilience 3.61 on average, and clinical competence 3.48 on average. It was found that clinical competence had significantly positive correlations with professional self-concept (r=.58, p<.01) and ego-resilience (r=.44, p<.01). According to regression analysis, the factors affecting clinical competence were professional self-concept, ego-resilience, and academic grades in order, and explanatory power was 39.5%. Conclusions. Given the above results, in order to improve clinical competence of nursing students, nursing educational institutes need to find an educational plan which can contribute to increasing professional self-concept, ego-resilience, and academic grades.