Background:Numerous empirical evidences have shown that social and environmental circumstances and social relations have an important impact on pregnancy outcomes, women's ability to cope with stressful situations, and childbirth pain management. The present study was conducted to determine the relationship between perceived social support and fear of childbirth.Materials and Methods:The present descriptive correlational study was conducted on 270 nulliparous pregnant women who referred for pregnancy care in 2016. The subjects were selected through convenience sampling method. The data collection tools were a demographic characteristics form, the Multidimensional Scale of Perceived Social Support (MSPSS), and the Wijma Delivery Expectancy/Experience Questionnaire (W-DEQ). The collected data were analyzed using descriptive and inferential statistics tests.Results:The mean perceived social support score of the participants was 77.90 and a significant correlation was observed between the perceived social support score and fear of childbirth score (β = −0.18, p = 0.004). The participants' mean score of fear of childbirth was 36.8. The results of study after the evaluation of the effect of predictive variables on the fear of childbirth are as follows: pregnancy preparation classes: (β = 3.50, p = 0.220); observation of natural childbirth videos: (β = 5.26, p = 0.040); and use of educational software: (β =5.82, p = 0.080).Conclusions:In order to reduce the fear of childbirth, women's social support structure during pregnancy should be assessed. Moreover, demographic characteristics form the structure and determine the extent of individuals' social network and, through the evaluation of these characteristics during pregnancy, the rate of effective support can be predicted in individuals.