OBJECTIVE: This study investigated phubbing (the act of ignoring one's companion or companions to pay attention to one's smartphone) and examined the factors affecting phubbing among nursing students in South Korea. METHODS: A cross-sectional survey design was adopted, and a self-reported questionnaire was used. Data were collected from 200 nursing students in two cities. Self-administered questionnaires included demographic data, smartphone addiction, media multitasking motivation, interpersonal competency, and phubbing. RESULTS: Phubbing was positively correlated with smartphone addiction (r=0.41, p<0.001) and media multitasking motivation (r=0.16, p<0.05), and negatively correlated with interpersonal competence (r=-0.51, p<0.001). Factors influencing nursing students' phubbing were interpersonal competency (β=-0.59, p<0.001), media multitasking motivation (β=0.24, p<0.001), smartphone addiction (β=0.19, p<0.01) and interpersonal relationships (β=0.14, p<0.05). The model including these variables accounted for 43% of variance in phubbing. CONCLUSION: Nursing students showed a moderate level of phubbing, and interpersonal competency was an important factor for reducing their phubbing of nursing students. Since phubbing occurs frequently among nursing students, educators in nursing are required to develop and implement active interventional measures to help nursing students avoid phubbing and improve their interpersonal relationships by increasing their empathic ability and communication skills.