Introduction: Acute lower respiratory infections (ALRIs) contribute to major disease associated mortality and morbidity among children under 5 years. Research suggests that low Hemoglobin (Hb) levels and Vitamin D Deficiency are associated with ALRI. The objective of this study was to know the association of low hemoglobin levels and vitamin D Deficiency with ALRI in children aged 6 months to 5 years. Materials and methods: The present study was a hospital based prospective study conducted over a period of one year, at KIMS Hospital and Research centre, Bengaluru. Children hospitalized for ALRI at KIMS Hospital, Bangalore were included as cases; hospitalized children (6months to 5years) other than respiratory illness were included as controls. Results: Among the cases, Vitamin D Deficiency, Vitamin D Insufficiency and Normal Vitamin D levels were seen in 70% (n=35), 28% (n=14), 2% (n=1) children respectively with Mean ± SD Vitamin D levels of 17.66 ± 5.53 ng/ml while controls had 16% (n=8), 24% (n=12), 60% (n=30) children respectively with a Mean ± SD Vitamin D level of 34.38 ± 13.87 ng/ml with p value <0.001. Among cases 48% (n=24) and 52% (n=26) children had Hb levels below 11g/dl and Hb above 11 g/dl respectively. While among controls 28% (n=14) and 72% (n=36) children had Hb below 11g/dl, and Hb above 11 g/dl, respectively. We found a significant correlation between Vitamin D levels and severity of ALRI with a p value of 0.03, a significant correlation between severity of ALRI and Hb levels with a p value of <0.01 and a significant correlation between Severe ALRI and combined low Hb and Vitamin D deficiency with p<0.0007. Conclusion: The study shows a significant correlation between low Hb levels and Vitamin D deficiency with increased susceptibility to ALRI. Severity of ALRI is inversely related to Vitamin D levels and Hemoglobin levels and more severe with combined deficiency.