Background. Obesity is considered a low-grade inflammatory state and has been associated with increased acute phase proteins as well as changes in serum fatty acids. Few studies have assessed associations between acute phase proteins and serum fatty acids in morbidly obese patients. Objective. To investigate the relationship between acute phase proteins (C-Reactive Protein, Orosomucoid, and Albumin) and serum fatty acids in morbidly obese patients. Methods. Twenty-two morbidly obese patients were enrolled in this study. Biochemical and clinical data were obtained before bariatric surgery, and fatty acids measured in preoperative serum. Results. Orosomucoid was negatively correlated with lauric acid (P=0.027) and eicosapentaenoic acid (EPA) (P=0.037) and positively with arachidonic acid (AA) (P=0.035), AA/EPA ratio (P=0.005), and n-6/n-3 polyunsaturated fatty acids ratio (P=0.035). C-Reactive Protein (CRP) was negatively correlated with lauric acid (P=0.048), and both CRP and CRP/Albumin ratio were negatively correlated with margaric acid (P=0.010, P=0.008, resp.). Albumin was positively correlated with EPA (P=0.027) and margaric acid (P=0.008). Other correlations were not statistically significant. Conclusion. Our findings suggest that serum fatty acids are linked to acute phase proteins in morbidly obese patients.