Objectives: This study investigated the factors influencing organizational socialization of new dental hygienists and provides basic data for successful organizational socialization. Methods: Data were collected using self-report questionnaires from 199 new dental hygienists of dental clinic and hospital between June and September 2018. Data analysis using SPSS 22.0 included Independent t-test, one way ANOVA, Scheffe post-hoc test, Pearson correlation coefficients, and multiple regression analysis. Results: The new dental hygienists’ professional self-concept, interpersonal ability, and organizational socialization value were 3.27±0.50, 3.55±0.45, and 3.03±0.37, respectively. There were significant positive correlations between professional self-concepts, interpersonal relations, and organizational socialization. A positive correlation was found between professional self-concept and interpersonal relations. Factors affecting organizational socialization of new dental hygienists included the strength of work, interpersonal relations, and professional self-concept. Professional self-concept was the most influential factor leading to 54.7% of the variance in organizational socialization. Conclusions: Therefore, to improve the organizational socialization of new dental hygienists and reduce the turnover rate, it is necessary to develop and implement programs promoting professional self-concept and interpersonal relations.