The hypothesis that dietary supplementation with LC-PUFAs may improve clinical recovery of malnourished children with damaged small intestinal mucosa secondary to chronic diarrhea, was tested. Patients <3y of age, with severe marasmus, kwashiorkor or mixed forms of malnutrition, admitted for chronic diarrhea (>15d), with dehydration <7% and who suffered intestinal infections were evaluated. Many also suffered systemic infections. Cases were randomly incorporated to one of two groups: after oral and iv hydration patients received for 3 weeks an oral formula consisting of casein hydrolisate enriched with cystine, glucose polimers, vitamins and minerals to fulfil daily requirements and fats to provide 40% of calories. In G1 (n=23) fats were provided by milk, vegetable oil and LC-PUFAs (n-3, n-6) (purified phospholipid concentrate) while in G2 (n=21) no LC-PUFAs were added. Patients were weighed daily. Only two patients had negative fecal swabs; as a mean two agents were identified per patients (range 2-6). On Days 3 and 21 after admission light microscopy of jejunal mucosa, disaccharidases activities and fatty acids were assessed in the mucosa. Plasma triglycerides in plasma and fatty acids in plasma, in erythrocyte membranes cholesterol esters and phospholipids fractions were measured. Both groups recovered satisfactorily, mean weight gain was 40 and 50 g/day in the last week of admission, respectively. Mild to moderate changes observed by light microscopy did not improve in either group; maltase, lactase and sacarase activities were very low on admission and only maltases improved after 3 weeks (p<0.03). Plasma triglycerides were 96 and 74 in G1 and 87 and 93 mg/dl on admission and after 3 weeks, respectively. Despite severe malnutrition fatty acids in all fractions were adequate in both measurements. No signs of deficiencies were observed. Administration of PUFAs was not associated with better outcome of the parameters measured. Profect CII*-CT92-0078.