PURPOSE: This study was conducted to identify the protective factors that influence suicide probability in religious male high school students. METHODS: The data was collected from Nov. 5 to Dec. 10, 2009. Data were collected by self-report questionnaire from 255 students selected from 2 religious male high schools in B city. The instruments for this study were the Suicide Probability Scale for Adolescence (SPS-A), Inventory Parents Peer Attachment-Revision (IPPA-R), Spiritual Well-being Scale (SWBS), and Ego-identity Scale. The data were analyzed using t-test, one-way ANOVA, Scheffe test, Pearson correlation coefficients and stepwise multiple regression with the SPSS 14.0 program. RESULTS: The protective factors of suicide probability in religious male high school students were identified as existential spiritual well-being (beta= -.46, p<.001), self-identity (beta= -.30, p<.001), and mother attachment (beta= -.21, p<.001). These three factors explained 61.5% of the variance in suicide probability. CONCLUSIONS: The results suggest that improvement in spirituality, ego-identity, and mother attachment for religious male high school students is important to reduce the probability of suicide.