The oral health of pregnant mothers is one of the important factors affecting their health and their fetus health. Due to the poor oral hygiene of pregnant women and the requirement of appropriate solutions for this issue, gathering sufficient information on the oral health of the target population is essential. Therefore, this study was conducted to evaluate the oral health status of pregnant mothers referring to the educational centers Al-Zahra and Tabriz Dental School. Method and material: This descriptive cross-sectional study was performed on 60 pregnant mothers during the first half of 2019. They had referred to Al-Zahra Medical Training Center and Tabriz Dental School. For each case, a checklist includes demographic information and oral examination. Oral examinations include a Simplified Oral Health Index (OHI-S), Gingival Index (GI), and Plaque Index (PI). Finally, linear and logistic regression models were used to evaluate the relationship between studied variables. Results: 60 pregnant mothers were studied, 25% of them did not visit a dentist and 10% did not brush their teeth. OHI-S (0-3.33) was 1.08, PI (0-3) was 1, and GI was 0.90 ± 1.98. Also, 80% of the studied population was diagnosed with gingivitis. A significant relationship was observed between PI and the location of residency of pregnant mothers. 88.3% of pregnant mothers brushed their teeth, 26.7% of them used salt water, 18.3% used floss, and 5% of them used mouthwash. There was a significant relationship between education and oral hygiene routine. Also, pregnant mothers who used saltwater had a better GI. Conclusion: The result of our study indicated poor oral and dental hygiene of pregnant mothers and this is more evident among mothers who had lower socioeconomic status and lower level of education.