The purpose of this study was to examine factors affecting the professional identity of dental hygienists in an attempt to raise awareness of the necessity of professional identity building for dental hygienists, to spread awareness of dental hygienist as one of professions, and to boost the pride of dental hygienists. The subjects in this study were 268 dental hygienists in Seoul and Gyeonggi Province. After a survey was conducted, the collected data were analyzed. The findings of the study were as follows: 1. The dental hygienists investigated got a mean of 3.44, 3.81 and 3.46 on professional identity, professional attitude and job satisfaction respectively. 2. In regard to the relationship of the general characteristics to professional identity, those who were older, whose career was longer, who worked in public dental clinics and who were married were statistically significantly ahead of their counterparts in that aspect. 3. Concerning connections between the general characteristics and professional attitude, age, career and marital status made statistically significant differences to that. As to links between the general characteristics and job satisfaction, there were statistically significant intergroup gaps according to age, career, service area, martial status and the field of job. 4. As for the correlation of the variables, better professional identity led to better professional attitude and higher job satisfaction. 5. In relation to factors affecting professional identity, better professional attitude, longer career and higher job satisfaction had a better impact on professional identity. Those factors made a 55% prediction of that.