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 detceted moderate to high levels of propoxur, chlorpyrifos and cypermethrin rcsistanec. Synergism studies suggested possible involvcmcnt of monooxygcnasc and cstcrasc in the rcsistancc in thcsc strains. Laboratory assays of the bait stations against all fivc strains showcd similar rcsults when compared to that of the laboratory susccptiblc strain. Ficld efficacy study was donc by placing 15 bait stations in the kitchen of cacli prcmisc whcrc hcavy infcstation of Gcr~nan cockroachcs had previously bccn 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.