Purpose: The purpose of this study was to identify the factors influencing Symptoms of Stress among hospital staff nurses. Method: Data was collected by questionnaires from 249 hospital staff nurses in three General Hospital. The data were analyzed using descriptive statistics, pearson correlation coefficients, and stepwise multiple regression. Results: The score of the symptoms of stress showed a significantly positive correlation with the score of work stress(r=.22, p=.00). The symptoms of stress showed a significantly negative correlation with the score of social support(r=-.28, p=.00), self efficacy(r=-.31, p=.00), and hardiness(r=-.24, p=.00). The most powerful predictor of symptoms of stress was social support and the variance explained was $16\%$. A combination of social support, ways of coping, and work stress account for $32\%$ of the variance in symptoms of stress among hospital staff nurses. Conclusion: This study suggests that social support, ways of coping, self efficacy, hardiness, and work stress are significantly influencing factors on symptoms of stress among hospital staff nurses.