Background: Nursing students must have the desired level of professional socialization to acquire the necessary roles and values to participate in the health care system. The process of socialization is part of the self-concept. Objectives: The aim of this study was to determine the level of socialization of nursing students and its relationship with self-esteem. Methods: This was a cross-sectional descriptive study. Data were collected from 166 nursing students. Data collection tools were demographic, professional socialization, and self-esteem questionnaires. The collected data were analyzed using descriptive and inferential statistical methods by SPSS 16. Results: The average scores of professional socialization and self-esteem were 174.87 ± 19.5 and 5.65 ± 5.10, respectively. Professional socialization was moderate in the majority of the participants (54.80%). The dimensions of “valuation and knowledge of the profession” and “management and organizational policies” had the highest and lowest averages, respectively. There was a positive and significant relationship between professional socialization and all its dimensions with self-esteem (P < 0.05). Also, there was a significant relationship between “professional socialization” and “interest in the field” as well as “the adaptation of the field to the ideas after entering the university”. Conclusions: By considering strategies, such as creating a positive attitude towards the nursing profession in students, professors can create a sufficient sense of self-esteem in different clinical settings and, consequently, strengthen professional socialization.