Background: Almost a third of Afghan women living in Iran are at childbearing age. Antenatal care (ANC) is an inextricable part of healthy pregnancy and could prevent the adverse birth outcomes. Almost 97% of Iranian expectant women are receiving adequate ANC (4 or more visits). However, the situation for pregnant Afghan women is unclear. Some studies indicated low access to ANC among Afghan women. In the present study, we aimed to explore the sociodemographic factors and potential barriers associated with adequate ANC among Afghan women in Iran.Methods: A cross sectional study was conducted between June 2019 and August 2019. Using time location sampling (TLS), we recruited 424 Afghan women aged 18-45 years old at three health centers in south region of Tehran. The data were collected on sociodemographic characteristics and the reported reasons for inadequate ANC using a questionnaire and analyzed applying bivariate, and multivariate analyses. Factor analysis was performed to reduce the number of potential reasons for inadequate ANC in order to improve the precision of regression analysis.Results: Almost a third of Afghan women in this study had adequate ANC (≥ 8 visits). The women in older age group, those with higher education and family income, women with longer length of stay, those of legal status were more likely to have adequate ANC. In multivariate analysis, the poor knowledge and attitude toward ANC (AOR = 0.06; 95% CI [0.03-0.15]), the poor quality of services (AOR = 0.17 95% CI [0.07-0.41]); and to some extent, the difficulties in access (AOR = 0.33; 95% CI [0.11-1.00]) were the main obstacles toward adequate ANC among the study population. Conclusion: Our study emphasized the important role of the personal knowledge and attitude toward ANC with adequate antenatal care among Afghan women in Iran. This could be addressed by well-oriented interventions and health education for Afghan women. The collaboration between central government with international agencies should be directed toward enhancing the social support, promoting the awareness and knowledge, and expanding the safety net services to improve the access and quality care among Afghan women in Iran.