Partial hydrogenation of polyunsaturated FAMEs has been investigated on a Pd/C catalyst. The effect of type of reactor: batch and continuous flow reactors, on the FAME composition and properties of a biodiesel product were studied. In addition, many characterization techniques such as XRD, BET, FE-SEM, and CO-chemisorption were used to examine the prepared catalysts. The result showed that the partial hydrogenation of polyunsaturated FAMEs in a batch-type reactor provides higher selectivity towards C18:1 than that of a continuous-flow reactor. However, at the low conversion (78%); selectivity of C18:1 obtained from both types of reactors were almost the same. (C) 2012 Elsevier B.V. All rights reserved.