This study ^[4] sought to examine the association between use of virtual social networks and social isolation among high school girls in Shahrekord. The research method was survey. The statistical population of the study comprised all female high school students in Shahrekord from among whom 390 students were selected via multi-stage cluster sampling method. To collect the data, Loneliness Scale (Gierveld & Kamphuis, 1985) was used which consists of 11 items and measures emotional and social loneliness. The face validity of the measure was established by conducting expert review and Cronbach's alpha coefficients for emotional loneliness, social loneliness, and social isolation were 0.73, 0.76, and 0.79, respectively. In addition, a researcher-made questionnaire was utilized to measure use of virtual social networks. This scale consisted of 13 items and Cronbach’s alpha showed the questionnaire to reach acceptable reliability, α= 0.93. The analyses revealed that the students’ average social isolation score was less than the theoretical mean. The results also showed that there was a significant, inverse relationship between use of virtual social networks and students’ level of social isolation. However, no significant association was observed between students’ grade level, age, and level of social isolation.