Objectives: the aim of this study was to assess the severity and type of nutritional deficiencies observed in patients with benign and malignant obstructive jaundice (OJ)., Method: in this prospective cross-sectional study 51 patients with OJ (21 with benign and with 30 malignant obstruction) were investigated. Nutritional status was assessed by anthropometric parameters (ideal body weight, midarm muscle area and skinfold thickness), visceral proteins, creatinine height index and total lymphocyte count. Observed values in patients with OJ were normalized to the percentage value of the lower limit of normal (obtained from 17 healthy subjects matched for age and sex) and averaged to obtain a total score for protein-energy malnutrition., Results: forty-two (82%) patients with OJ had protein-calorie malnutrition (PCM). Malnutrition was mild in 55%, moderate in 35% and severe in 10%. Severity of PCM was associated with intensity (p < 0.05) and duration of jaundice (p < 0.01). Kwashiorkor (74%) was the dominant type of malnutrition. PCM was common in benign (71%) as well as in malignant obstruction (90%), but the total score (92 +/- 20 vs 80 +/- 19; p < 0.05) and the proportion of mild PCM in patients with benign obstruction (80% vs 41%, p < 0.01) was significantly higher than in patients with malignant tumors., Conclusions: a high percentage of patients with OJ had PCM. The degree of nutritional alteration was associated with the intensity of jaundice. Malnutrition was equally prevalent among patients with benign obstructions and patients with malignant causes of biliary obstruction, although it was more severe in the latter. Acute malnutrition (kwashiorkor) was the dominant type of malnutrition in both groups of patients.