Based on the structure of the previously identified leads, new series of compounds containing 1,2,4-oxadiazole core was designed. A small, diverse library of 51 compounds including both 2-(acylamino)ethyl and 2-ureidoethyl side chains was synthesized using parallel chemistry and tested for antiproliferative activity against prostate cancer DU-145 cell line. Four hit compounds - all belonging to 2-ureidoethyl series - were identified and three compounds were confirmed as 10-20 μM inhibitors. The similarity in compounds' periphery and the data obtained previously suggest a similar mode of action for these compounds which was postulated as tubulin inhibition and was confirmed by in silico docking. These data provide further evidence for the privileged character of 1,2,4-oxadiazoles in antiproliferative compound design.