en General پژوهشي Research Article Background:Happiness is recognized as a vital dimension of mental health and has a significant impact on the quality of nursing care. Social responsibility is likewise a key component of professional practice in nursing, influencing ethical standards and service delivery. Objectives:This study aimed to examine the relationship between social responsibility and happiness among nurses working in hospitals affiliated with Tehran University of Medical Sciences (TUMS). Methods:A cross-sectional design was employed in 2023, involving 240 nurses selected through stratified random sampling from university-affiliated hospitals. Data were collected using a demographic survey, Carroll&rsquo;s Social Responsibility Questionnaire, and the Oxford Happiness Questionnaire (OHQ). Statistical analyses were conducted using SPSS version 16. Descriptive statistics (means and standard deviations) and inferential analyses, including Pearson&rsquo;s correlation coefficient, were utilized. A P-value < 0.05 was considered statistically significant. Results:Over half of the nurses (57.3%) reported moderate levels of happiness, with a mean score of 42.3 &plusmn; 5.85. In contrast, 96.7% of participants exhibited low or very low levels of social responsibility (68.1 &plusmn; 9.85). Pearson&rsquo;s correlation analysis revealed a significant negative relationship between social responsibility and happiness (r = -0.559, P < 0.001), indicating that higher levels of social responsibility were associated with lower levels of reported happiness. Conclusions:Increased social responsibility was inversely associated with nurses&rsquo; happiness and mental well-being. Nursing administrators are encouraged to identify highly committed personnel and implement supportive policies and motivation strategies that balance professional responsibility with psychological well-being. Happiness,Social Responsibility,Nursing,Mental Health,Iran 0 0 http://mcj.bums.ac.ir/browse.php?a_code=A-10-1-329&slc_lang=en&sid=1 Mojtaba Azar 10031947532846003343 0009-0002-0945-3113 No Student Research Committee, School of Nursing and Midwifery, Tehran University of Medical Sciences, Tehran, Iran Mohammadali Cheraghi 10031947532846003344 10031947532846003344 No Nursing and Midwifery Care Research Center, School of Nursing and Midwifery, Tehran University of Medical Sciences, Tehran, Iran Alireza Shahedi 10031947532846003345 10031947532846003345 No Student Research Committee, School of Nursing and Midwifery, Tehran University of Medical Sciences, Tehran, Iran Fatemeh Hajibabaee 10031947532846003346 10031947532846003346 Yes Nursing and Midwifery Care Research Center, School of Nursing and Midwifery, Tehran University of Medical Sciences, Tehran, Iran. Email: hajibabaeefateme@yahoo.com Roohangiz Jamshidi Orak 10031947532846003347 0009-0009-3143-1982 No Nursing Care Research Center, Iran University of Medical Sciences, Tehran, Iran