Background: In Severe Acute Malnutrition (SAM) clinical and biochemical abnormalities are commonly observed. In this institute author observed that many children of complicated SAM had bleeding manifestations but there is no defined prevalence of vitamin K deficiency in SAM that’s why author have planned this study.Methods: This was the hospital based prospective study conducted in 150 complicated SAM children. All children were treated according to WHO protocol for SAM management. Prothrombin Time (PT), International Normalized Ratio (INR), activated Partial Thromboplastin Time (aPTT) along with routine investigations were done on admission. All the collected data was managed and analyzed with standard software Biostatics (SPSS Version 20).Results: Total 150 complicated SAM children were studied for prevalence and clinical manifestations of vitamin K deficiency. Mean age of children was 17.03±11.0 months, 52.0% were male and 48.0% were female children. Average weight was 5.92±1.57 kg. Average height/length was 70.66±8.38 cm and mean MUAC was 10.47±1.31 cm. Out of 150, 42(28%) children had abnormal INR and 28(18.7%) had abnormal aPTT with abnormal INR. The mean INR was 2.11±1.1 and mean aPTT was 45.30±9.59 in children those had abnormal INR. Twelve out of 42(28.6%) had various bleeding manifestations and majority (66.6%) had gastrointestinal bleeding.Conclusions: More than one fourth children (28%) of complicated SAM children are having vitamin K deficiency and majority of children present with gastrointestinal bleeding.