Background: Severe acute undernutrition remains a major contributor to childhood morbidity and mortality, particularly in low- and middle-income countries. It is influenced by a complex interplay of socio-demographic, feeding, and healthcare-related factors, many of which are preventable. Identifying these determinants is essential for developing effective interventions. Objectives: To identify socio-demographic, feeding, and healthcare-related risk factors associated with severe acute undernutrition among children aged 6–59 months. Methods: A hospital-based case–control study was conducted in a tertiary care centre, including 60 children aged 6–59 months. Thirty children diagnosed with severe acute undernutrition constituted the case group, while 30 age-matched children with normal nutritional status served as controls. Data regarding socio-demographic characteristics, infant feeding practices, immunization status, and birth interval were collected using a structured questionnaire. Anthropometric measurements were recorded using standard techniques. Statistical analysis was performed using appropriate tests, and a p-value <0.05 was considered significant. Results: Significant associations were observed between severe acute undernutrition and maternal illiteracy (70.0% vs 33.3%; p=0.005), paternal illiteracy (46.7% vs 3.3%; p=0.001), and lower socioeconomic status (96.7% vs 10.0%; p=0.001). Feeding-related factors such as lack of exclusive breastfeeding (73.3% vs 16.7%; p=0.001) and inappropriate complementary feeding (100% vs 20.0%; p=0.001) were strongly associated. Incomplete immunization (86.7% vs 20.0%; p=0.001) and shorter birth interval (≤2 years) (59.1% vs 6.3%; p=0.001) were also significant. Conclusion: Severe acute undernutrition is strongly associated with modifiable socio-demographic and feeding practices. Strengthening maternal education, promoting optimal infant feeding, improving immunization coverage, and ensuring adequate birth spacing are crucial for prevention.