Background <p>Immigrant mothers, having a desire to breastfeed doesn’t necessarily mean they will do it, particularly when migration throws their traditional support networks into disarray and turns up the volume on daily stressors. Nigerian mothers in Malaysia are culturally inclined to breastfeed but face their own challenges as they negotiate motherhood thousands of miles away from home with no extended family or community support system.</p> Objective <p>This study examined breastfeeding knowledge, intended breastfeeding practices, and maternal stress among Nigerian immigrant mothers living in Kuala Lumpur, Malaysia.</p> Methods <p>A community-based cross-sectional study was conducted among 88 pregnant Nigerian immigrant women in their third trimester residing in Kuala Lumpur. Participants were recruited using purposive snowball sampling through community networks, religious organizations, student associations, social media groups, and referrals. Data were collected using structured questionnaires assessing socio-demographic characteristics, breastfeeding knowledge, intended breastfeeding practices, and maternal stress. Data were analyzed using descriptive statistics, ordinal logistic regression, and Spearman correlation analysis, with statistical significance set at <i>p</i> &lt; 0.05.</p> Results <p>Participants were aged 18–45 years, with half (50.0%) aged 26–35 years. Although 92.0% of participants intended to breastfeed, only 8.0% planned to initiate breastfeeding within the first hour after birth and 39.8% intended to exclusively breastfeed for six months. Knowledge of infant-related breastfeeding benefits was relatively high, whereas knowledge of maternal benefits (43.2%) and breast milk expression techniques (26.1%) was considerably lower. Maternal stress was highest in the domains of household burden (mean = 2.75, SD = 0.96) and fatigue (mean = 2.69, SD = 0.86). Higher education was significantly associated with greater breastfeeding knowledge and intended breastfeeding exclusivity. Breastfeeding knowledge was positively correlated with intended exclusivity (<i>r</i> = 0.454, <i>p</i> &lt; 0.001) and breastfeeding duration (<i>r</i> = 0.294, <i>p</i> = 0.006), while maternal stress was negatively associated with intended breastfeeding duration (<i>r</i> = -0.348, <i>p</i> = 0.001). Breastfeeding knowledge was also inversely correlated with maternal stress (<i>r</i> = -0.331, <i>p</i> = 0.002).</p> Conclusion <p>A clear disconnect exists between breastfeeding intention and planned practice among Nigerian immigrant mothers. This gap is driven by insufficient practical knowledge and elevated maternal stress- particularly from social isolation, household overload, and unsupportive environments. The findings of this study underscore the need for culturally grounded, stress-sensitive interventions that go beyond information delivery to include hands-on lactation support, peer networks, and integrated psychosocial care.</p>