Introduction: An individual’s assessment of his/her performance in life with regard to society must be defined as social health. In point of fact, a socially healthy individual views the community as a meaningful, understandable and potential set for growth and prosperity and feels that he/she belongs to society, is accepted by society and is involved in the development of society. The individual’s assessment of his/her performance in the community results from the quality of his/her relations with others, i.e. friends and social groups, of which he/she considers himself/herself to be a member.Accordingly, the aim of this paper is to assess the social health indicators of youth and young adults and factors affecting it (such as: happiness, social security, social capital, life satisfaction and quality of life). The theoretical framework of this study is based on a combined approach. With regard to social health, social capital, quality of life, security, happiness and life satisfaction, theories of Keyes, Bourdieu, Zapf, Giddens, Veenhoven & Argyle and Myers & Diener have been used respectively.Materials and Methods: In this study, the survey method used is descriptive correlational. The population of this study has consisted of all the 18- to 30-year-old citizens of Qaen City, located in South Khorasan Province, in 2015-2016. Also, a sample of 400 individuals has been selected, using cluster sampling method. Moreover, the level of analysis and the unit of observation in this study is the individual (micro-level). The information required of respondents was collected using both standardized and researcher-made questionnaires. Cronbach’s alpha was equal to 0.85%. The respondents’ findings were analyzed based on descriptive and inferential statistics and using SPSS Software (v.22).Discussion of Results and Conclusions: The results show that the level of social health of the youth and young adults under the study is above average. There is a positive and significant relationship between social capital, social security, quality of life, life satisfaction and happiness, and social health. That is to say, with an increase in social security, quality of life, happiness, life satisfaction and social capital, social health increases among the youth in the city. Based on the regression results, of the independent variables, the variables of happiness, quality of life and life satisfaction have been able to explain the dependent variable more strongly; however, the variables of social capital and social security, did not have a direct role in explaining the social health of youth. Accordingly, the more happiness, quality of life and life satisfaction there is among youth, the more social health there will be as well. Also, the two variables of social security and social capital affect the variable of social health indirectly and through the central dependent variable; that is, the variable of social security and the variable of social capital affect social health through the variables of happiness, social capital and quality of life and through the variables of life satisfaction and quality of life, respectively. In addition to this, the correlation coefficient (R) between the variables is 0.275; thus, in general it can be said that there is a moderate correlation between the independent and dependent variables. Based on these results, social capital indicators, such as trust, partnership and norms which have been eroded at community level, must be strengthened by governing bodies. This will help reduce social harms among society members and also enhance individuals’ health (including mental and social health). Also, if the individuals’ security is improved, we will witness a boom in partnership, prosperity and social cohesion of society members. Moreover, considering the fact that the quality of life of youth at the community level is a composite variable, by making some changes to the income level, living conditions, health, psychological pressure, leisure, happiness, social relations, etc., we could witness the effectiveness of this vari a ble in the social health of Iran’s current young population. Furthermore, existence of happiness as a variable directly affecting the social health of youth indicates that in the present society, this variable can improve skills and abilities such as efficiency, independence, education and health at different levels. Finally, existence of the variable of life satisfaction -for dealing with problems and expressing deep emotions- in the life of a young adult, can significantly affect his/her social health, and lack of this variable will lead to the emergence of mental illnesses, personality problems and individual harms. Consequently, dire events could be envisaged for society at the community level.