Purpose: The purpose of this study was to understand depression in women with endometriosis and to identify the factors influencing depression. Method: The instruments used were the Beck Depression Inventory for depression, Lemaire Scale for endometriosis syndrome, Mishel Uncertainty in Illness Scale-Community form (MUIS-C), the Rosenberg Self-esteem Scale, and Quality of Life (Endometriosis Health Profile Questionnaire; EHP-5) by Jones et al. The Subjects of Study were 118 outpatients diagnosed with endometriosis from 7 hospitals in Busan City and Kyungsangnam-do. Data was collected from Aug 1, 2004 to Jan 31, 2005. For statistical analysis of collected data, frequency analysis, analysis of variance, and stepwise multiple regression analysis were used with the SPSS statistical program. Result: The general characteristic showing a statistically significant difference in depression in the women with endometriosis was marital status. The score of the depression showed a significantly positive correlation with the score of endometriosis TSD(r= .464, p= .000), uncertainty(r= .393, p= .000), and quality of life(r= .543, p= .000). Depression showed a significantly negative correlation with the score of self esteem(r= - .557, p= .000). Stepwise multiple regression analysis revealed that the most powerful predictor of depression in the women with endometriosis was self-esteem ($R^2$=0.311). A combination of self esteem, quality of life, and total symptom distress accounted for $50.0\%$ of the variance in depression in women with endometriosis. Conclusion: The influencing factor on depression in women with endometriosis was self- esteem, quality of life, and endometriosis TSD. Further studies need to be done to identify methods of overcoming and the presentation of depression in endometriosis.