BackgroundTo control the spread of COVID‐19, Iran has adopted rigorous precautionary and preventive measures, particularly for vulnerable groups. Considering the effects of knowledge and attitudes about COVID‐19 on adherence to preventive measures, we examined women's knowledge, attitudes, and practices (KAP) from pregnancy to 6 weeks postpartum about COVID‐19 during this pandemic.MethodsIn a cross‐sectional study, 7363 women were recruited via an online questionnaire between June 23, 2021 and July 7, 2021. The questionnaire consisted of 27 questions, measuring KAP.ResultsMost of the participants had a good understanding of COVID‐19 (Mean: 7.30 out of 9, standard deviation [SD]: 1.27), but the knowledge of the disease's main symptoms and modes of transmission was at the lowest levels. The mean attitudes score was 31.47 out of 50 (SD: 7.70). The participants had good practices against COVID‐19 with a mean score of 35.48 out of 40 (SD: 3.94). To reduce anxiety and fear during the pandemic, half of our participants strongly emphasized the role of family emotional support. Income status and educational levels were the most significant variables influencing KAP (p‐value ≤0.001). A correlation was found between knowledge and practice scores (r = 0.205, p‐value = 0.001).ConclusionOur findings may serve to formulate awareness‐raising interventions and can be a guide to health policymakers and workers such as obstetricians, clinicians, and midwives for more effective educational communication emphasizing the COVID‐19 symptoms and transmission modes and rendering appropriate counseling, particularly on the importance of emotional family support during the pandemic.