Trihaloallyl and trihaloacryl derivatives were synthesized for wood preservative evaluation. It was shown in bioassays that the presence of iodine in the compounds is important for antifungal activity. Among the compounds tested, triiodo-and monobromodiiodo-allyl esters and -acryl esters were found to possess marked protective action to wood molds and wood decay fungi. 3-Ethoxycarbonyloxy-l-bromo-1,2-diiodopropene was chosen as the most promising potential wood preservative as it also showed insecticidal activity. -- AATA