Abstract. Ficld and laboratory performance of a commercially available hydramcthylnon-based bait station (Combat') wcrc conductcd against insccticidc-resistant German cockroach, Blattella get.tiin~zicn (Linn.) populations in fivc coffee-shops in Pcnang, Malaysia. Bioassay screening on FI generation of the field collected cockroaches using a modified W.H.O. glass jar method detected moderate to high levels of propoxur, chlorpyrifos and cypermethrin resistance. Synergism studies suggested possible involvement of monooxygcnase and esterase in the resistance in these strains. Laboratory assays of the bait stations against all five strains showed similar results when compared to that of the laboratory susecptiblc strain. Field efficacy study was done by placing 15 bait stations in the kitchen of cacli premise where heavy infestation of Ger~nan cockroaches had previously been found. At 4-wcck post-trcatmcnt, a rcduction of >90% was achicvcd in all prcmiscs. Suppression of thc cockroach population rcmaincd high up to 12 wccks with >80% rcduction in all populations.