Purpose: Interpersonal competence, a key competence for patient-centered care by nurses, should be understood. Therefore, factors influencing the interpersonal competence of nursing students should be identified to explore and enhance their interpersonal relationships during the undergraduate educational curriculum for nursing educators. In this study factors influencing interpersonal competence, especially on self-assertiveness and empathy in nursing students were identified and analysed. Methods: A cross-sectional study design was used for the study in two Korean nursing colleges with similar baccalaureate nursing curricula. A total of 251 nursing students from freshman to senior year completed a questionnaire to measure related factors that were assumed to influence nursing students’ interpersonal competence. Data were collected from October 11~31, 2016. Study variables included self-assertiveness, empathy, interpersonal competence, and socio-demographic status. Multiple regression analysis was used for data analysis. Results: Nursing students’ interpersonal competence was explained by personality (β=.22), self-assertiveness (β=.16) and empathy (β=.38). The explanatory power of these predictors was 26.8% (p<.001). Conclusions Nursing students’ interpersonal competence during the undergraduate nursing years can be enhanced by educational strategies that improve their interpersonal relationship as patient-centered care providers. Simultaneously, the attitude of the nurse educator is also important for nursing students who are to be treated as valuable learners and to improve students' empathy and self-assertiveness ability.