Abstract Malnutrition remains a leading contributor to morbidity and mortality among children under five years of age, particularly in low- and middle-income countries. This study examined the causes, effects, and preventive strategies of malnutrition among children aged 0–59 months in Langtang South Local Government Area (LGA), Plateau State, Nigeria, and assessed whether caregivers’ religious affiliation, occupation, and educational level were associated with perceived effects of malnutrition. A descriptive cross-sectional survey design was adopted. Structured questionnaires were administered to 200 mothers/caregivers of children under five, selected through random sampling, with items interpreted into Hausa for non-literate respondents. Data were analysed using descriptive statistics (frequencies, percentages and graph) and inferential statistics (chi-square test of independence, α = 0.05) via SPSS version 25. Inadequate/lack of food (64%) and lack of time to feed the child (17%) were the most frequently cited causes of malnutrition, while kwashiorkor (37%) and marasmus (25.5%) were the most frequently cited effects. Exclusive breastfeeding (44%) and adequate food security (23%) were the most widely known preventive strategies, although 2% of caregivers reported no knowledge of any preventive measure. Chi-square analysis showed a statistically significant difference in perceived malnutrition effects by religious affiliation (χ² = 25.72, df = 14, p = 0.028), but no significant difference by occupation (χ² = 32.27, df = 21, p = 0.055) or educational level (χ² = 29.07, df = 21, p = 0.112). The findings suggest that inadequate food access and caregiving time constraints, rather than a general lack of awareness, remain the principal drivers of child malnutrition in this community, and that religious affiliation — more than occupation or formal education — was associated with how caregivers perceived its effects. Community-based, culturally sensitive nutrition education and continued support for exclusive breastfeeding and household food security are recommended. Keywords: Child malnutrition; Under-five children; Determinants; Preventive strategies; Caregiver knowledge; Langtang South LGA.