During the coronavirus disease 2019 (COVID-19) pandemic, many individuals sought traditional and complementary medicine (T/CM) as an alternative to conventional healthcare, while also adhering to social distancing guidelines. Consequently, understanding the T/CM use among vulnerable populations, specifically pregnant women, and the communication practices between patients and healthcare providers regarding its use is crucial. This study assessed T/CM use among pregnant women in El Alto, Bolivia, during the COVID-19 outbreak and examined communication behaviors regarding T/CM use during antenatal consultations. A 48-item semi-structured survey was used to conduct a descriptive cross-sectional study of 271 postpartum women in two public hospitals in El Alto. Data analysis included chi-squared tests and logistic regression in SPSS ver. 26.0. Although 57% of women reported using T/CM during pregnancy, less than one-third of these women discussed their T/CM use with healthcare providers. However, over 70% of women were willing to disclose T/CM use if the discussion was initiated by healthcare providers. Potential predictors of T/CM disclosure included non-use of nutritional supplements during pregnancy and obtaining T/CM-related information from the mass media. Our findings highlight a significant communication gap between pregnant women and healthcare providers regarding T/CM use, despite their widespread use during public health crises such as COVID-19. Therefore, it is critical to develop interventions to improve communication practices and enhance the quality of care for pregnant women.