['Malnutrition is common in obstructive jaundice but is difficult to define. The aim of this study was to compare definitions of malnutrition in patients with obstructive jaundice to identify correlation with mortality, complications and length of hospital stay after intervention.', 'Prospective case-control study comparing 39 inpatients with obstructive jaundice with 21 controls. Body mass index (BMI), skin-fold thickness (TSF), mid-arm muscle circumference (MAMC), percentage weight loss, nutritional risk index (NRI) and malnutrition universal screening tool (MUST) were measured and compared. Duration of admission, interventions, complications and outcome were recorded prospectively.', 'Patients with obstructive jaundice were significantly malnourished compared to controls. Severe malnutrition was equally prevalent in benign and malignant disease. Malnourished patients had higher mortality and longer duration of stay after intervention compared to non-malnourished patients. NRI<83.5 was significantly associated with mortality and longer duration of hospital admission but not complication rate.'] Does nutritional risk index predict a high-risk population in patients with obstructive jaundice?