Objective The aim of this study was to evaluate the relationships between inflammatory parameters and lipid and phospholipids fatty acid (FA) profile in patients with ulcerative colitis (UC) and Crohn disease (CD). Method Ninety consecutive patients, admitted for surgery for UC or CD between December 2004 and April 2006, were enrolled in this cross sectional study. Disease activity (Seo and CDAI index), diet, inflammatory parameters, lipid profile and serum, subcutaneous and omental fatty acids (FA) phospholipids composition were assessed. Lipid and plasma phospholipids fatty acid profiles were also evaluated in a group of 33 healthy subjects, enrolled as controls. Data were expressed as mean +/- standard deviation and Pearson correlation and t test were used.Result Total and LDL cholesterol were significant lower in IBD patients compared to healthy controls (total cholesterol 163+/-43 vs 207+/-41 mg/dl, p=0.0001; LDL 92+/-37 vs 129+/-38 mg/dl, p<0.01). In the phospholipids fatty acid profile only the stearic acid (18:0), was significantly lower in the IBD patients (12,38 vs 14,12%). No correlation between erythrocytes sedimentation rates and lipid and phospholipids fatty acid was observed. On the contrary C-reactive protein (CRP) correlated significantly with HDL (r=-0.24, p=0.034), palmitic acid (16:0) (r=+0.49 , p=0.000) and saturated fatty acids (r=+0.28, p=0.002), dihomo-gamma-linolenic acid (20:3 n6) (r=-0.26, p=0.035), docosapentaenoic acid (22:5 n3) (r=-0.27, p=0.033), arachidonic acid (20:4 n6) (r=-0.26, p=0.041). Conclusion The lipid profile in IBD patients seems to reflect a condition of malabsorption. The weak correlations between CRP and some fatty acids may suggest that the inflammatory status of IBD patients involves also the serum phospholipids fatty acids composition. Modifications of fatty acid composition (e.g. with n3 fatty acid supplementation) could modify the effects of inflammation on these patients.