An efficient chemoenzymatic method for preparing conjugated linoleic acid (CLA) using free linoleic acid (LA) as a substrate is described. In the first step, LA was transformed into 10-hydroxy-cis-12-octadecenoic acid (HA) by the whole cells of Lactobacillus plantarum after 48 h of incubation. The preincubation of whole cells with 0.03% LA resulted in a better yield of HA (480 mg/g) compared to cells grown without LA. In a second fast microwave step, HA was converted to cis-9, trans-11-octadecadienoic acid in the presence of iodine as a catalyst over a silica gel surface. The advantage of this method in preparing cis-9,trans-11 CLA is simple via the whole cell bioconversion of LA into HA via L. plantarum followed by the fast microwave-assisted synthesis of cis-9,trans-11 CLA in higher yields.