Background: One of the most stressful professions in the world is psychiatric nursing. It is seen as a physically and psychologically demanding task for nurses. As a result, identifying effective solutions and factors that reduce stress and improve the mental health of nurses is critical. Aim of the study: was to assess relationship between compassion, self-efficacy and perceived stress among nurses working at Tanta Mental Health Hospital. Subjects and Method: Research design was a correlational descriptive research design. Setting: the study was conducted at the Tanta Mental Health Hospital which affiliated to Ministry of Health. Subjects: All available nurses working at previously mentioned setting at the time of data collection of the study and they were 75. Tools: Four tools were used. Tool 1: Socio-demographic characteristics structured questionnaire. Tool II: Compassion Scale. Tool III: Perceived stress scale. Tool VI: General SelfEfficacy Scale (GSE). Results: There are no statistically significant relation was found between psychiatric nurses' compassion and their perception of stress and highly negative statistically significant correlation was found between perceived stress and self- efficacy. Conclusion: The present study concluded that self-efficacy is important factor affecting on nurses'' stress. Nurses who have more self-efficacy are more likely to tolerate perceived stress. Meanwhile compassion in present study has no effect on stress among nurses. Recommendations: Engaged psychiatric nurses periodically in training periods or workshops to enhance both their self- efficacy, and compassion which help them to acquired skills and positive facets of mental health.