Knowledge, attitude and practice (KAP) about breastfeeding among postpartum mothers in Bayan-Ulgii province Background: Breastfeeding stands as a crucial determinant for the health of both mothers and newborns. However, its declining rates, observed globally including in Mongolia, pose a significant concern. Investigating the underlying causes of this decline is imperative for addressing this pressing issue. Materials and methods: Using the cross-sectional study design, we randomly selected postpartum mothers and assessed their knowledge, practices, and attitudes toward breastfeeding. This evaluation was conducted using a questionnaire derived from the Maternal and Child Health Book, distinguishing between primiparous and multiparous mothers from January to July, 2023. Results: The study comprised 112 mothers, including 36 primiparous and 76 multiparous mothers. A notable finding was the lack of pregnancy preparation among the majority of mothers, with only 67% reporting preconceptional folic acid intake, notably lower among primiparous mothers at 33%. Furthermore, 78.6% of mothers had not received prenatal training. Significantly, a higher proportion of multiparous mothers (72.7%) exhibited positive attitudes towards night breastfeeding compared to primiparous mothers (27.3%), indicating a statistically significant difference (p=0.003). Additionally, primiparous mothers demonstrated a lower attendance rate for breast preparation training (p=0.005), potentially leading to increased challenges with breast attachment (p=0.049) and nipple damage issues. Conclusions: The findings highlight concerning levels of unpreparedness for pregnancy among mothers, coupled with inadequate breast preparation, particularly evident among first-time mothers, leading to potential commitment issues and nipple complications. Further investigation is warranted, as these factors may contribute to the rising consumption of infant formula in the future.