Neighborhood relationships are regarded as declining social relations among citizens in metropolitan areas. In this research first the neighborhood relations were studied, then the hypothesis of weak relations of neighborhood residents were estimated in Tehran. The factors influenced the variables were investigated according to available theories and approaches. The study considered three viewpoints: Determinism theory, Compositional theory and Subculture theory. Neighborhood relations were explained regarding to two main components of social capital: social trust and social participation as well as the existence and use of public spaces. The data-gathering was conducted through 9 districts from down, center and up areas in Tehran by interviewing 270 respondents. The findings showed that the female and married respondents have a stronger tie to neighborhood relations than the male and married ones. Also, the variables of age, length of residency, type of housing ownership, level of neighbor satisfaction, social participation, interpersonal trust, beliefs on neighbors, place belonging and the use of public spaces have a positive effect on neighborhood relations. On the contrary, the variables of employment, membership in secondary groups, population density and size of neighborhood units, relocation, rationalization, and complex division of labor were in negative relations to neighborhood relationships. As a result, by recognizing the impact of these factors, the way can be paved to prevent the reduction of face-to-face relationships with the neighbors, who are in the adjacent social network outside their homes, and neighborhood relationships can be turned into a social asset. Social participation as a systematic process, in which the people involve consciously and collectively with considering certain objectives, and share the power resources, was found as the most effective factor on the continuity of neighborhood relationships.