Background and Purpose: Social support is considered as a facilitator of health behaviors in women. This study aimed to evaluate and compare the status of social support and its associated dimensions in pregnant and non-pregnant women. Methods: This analytical study was conducted on 310 pregnant and non-pregnant women referring to the health-care centers of Zarqan city in Shiraz, Iran in 2011. Participants were selected via convenience sampling. Data collection tools included demographic questionnaire and Social Support Appraisals (SS-A) scale. Data analysis was performed in SPSS V.16 using descriptive (frequency, percentage, mean, and standard deviation) and inferential statistics (Chi-square, T-test, and Pearson's and Spearman's correlationcoefficient). Results: In non-pregnant women, mean of the total social support was 40.08±2.80, and mean scores of support from friends, spouse, family and others were 12.08±1.33, 14.02±1.56, 14.53±0.96 and 13.54±1.09 respectively. Among pregnant women these values were 39.52±2.85, 11.72±1.59, 14.54±1.12, 14.38±1.06 and 13.41±1.18, respectively. The total support and support from friends were significantly higher in non-pregnant women compared to pregnant women (P = 0.05 and P = 0.03, respectively). On the other hand, support from the spouse was significantly higher in pregnant women compared to non-pregnant women (P = 0.01). Moreover, a significant correlation was observed between the total scores of social support and employment status of spouse among pregnant women (P<0.01). Also, significant associations were found between social support and employment status of spouse (P<0.01), mother' availability (P<0.05), and education status (P<0.05). Family support in pregnant women had a significant relationship with the employment status of spouse (P<0.05), father's availability (P<0.01), and mother's availability (P<0.05). In addition, there was a significant correlation between the social support from others and employment status of the pregnant women (P<0.05). Conclusion: According to the results of this study, there were significant differences in the total scores of social support and mean scores of support from the spouse and friends between pregnant and non-pregnant women. It seems that physical and psychological changes during pregnancy largely influence the perception of expecting mothers towards social support.