Background: There is a long history of traditional/complementary medicine (T/CM) use by women during lactation. While it is important to evaluate such use within a scientific paradigm to ensure efficacy and safety, knowledge about the prevalence and characteristics of T/CM use during lactation is limited. This study aimed to generate preliminary data on the prevalence, perceptions and behaviors related to T/CM use by women living in Macau during lactation. Methods: Between April to June 2018, women aged 18 years or above who had breastfed within the previous 12 months were invited to complete a questionnaire which asked about their perceptions and behaviors related to the use of T/CM while breastfeeding. Chi-square analysis and logistic regressions were used to conduct data analysis. Results: A total of 500 women completed the survey with 62.6% (95% CI 58.37-66.83) reporting use of at least 1 T/ CM while breastfeeding. Of these 48.9% (95% CI 44.67 to 53.13) believed T/CM were safe to take during lactation and 55.6% (95% CI 51.37 to 59.83) suggested there were inadequate resources to assist making an informed decision. Working status, monthly family income and the presence of a breastfeeding-related health problems were associated with T/CM use (all p< 0.05). The most commonly used T/CM were Tetrapanax papyriferus, lecithin, Vaccaria segetalis, docosahexaenoic acid and Trigonella foenum-graecum commonly referred to as Fenugreek. The most common reasons for using T/CM were ‘to unblock milk ducts’, ‘to increase milk supply’ and ‘to improve baby development’. Women were recommended to use T/CM from multiple sources; 15.0% from health personnel (HP) only, 40.0% received recommendations from non-HP only; and 42.2% from both.Conclusions: The use of T/CM by women during lactation is common in Macau. The current support and resources available to women during the breastfeeding period to make informed decisions about T/CM use is not standardized nor integrated. The gaps identified in this study provide an opportunity to develop resources and a more defined role for HPs to ensure the appropriate and safe use of T/CM in this population.