Purpose: This study purposed to identify the levels of self-awareness, other-awareness, interpersonal relation competence, and smartphone and Internet addiction and identify the influence of self-awareness, other-awareness, and interpersonal relations competence on smartphone and Internet addiction in nursing students. Methods: Study participants were 479 nursing students who completing structured self-report questionnaires. Data were analyzed using descriptive statistics, independent t-tests, one-way ANOVA, Pearson’s correlation coefficients, and multiple regression. Results: The participants’ smartphone addiction risk was shown to be 24.2%. Among the predictors, gender (β=-.11, p<.05), academic year (β=.15, p<.01), self-awareness (β=-.12, p<.05) other-awareness (β=.29, p<.001), and interpersonal relation competence (β=-.20, p<.001) had significant influences on smartphone addiction. The explanatory power of this regression model was 16.0% (F=10.21, p<.001). The participants’ Internet addiction risk was shown to be 29.0%. Among the predictors, academic year (β=.12, p<.05), major satisfaction (β=-.17, p<.001), other-awareness (β=.22, p<.001), and interpersonal relation competence (β=-.18, p<.001) had significant influences on Internet addiction. The explanatory power of this regression model was 13.0%(F=8.48, p<.001). Conclusion: It is necessary to develop the early detection and monitoring of smartphone and Internet addiction among nursing students. In addition, specific programs focused on promoting self-awareness and other-awareness for smartphone and Internet addiction should be developed.