Study results obtained by the use of permethrin impregnated cloths against the dengue haemorrhagic fever vector Aedes aegypti (L) are reported and discussed. Field trials were carried out in sub-district of Ungaran, Semarang regency. Houses were provided with cloths made of 65 % polyester fiber 35% combed cotton, brown colour impregnated with permethrin 25%EC with a dosage of 0.40 ga.i./m2 installed on the wall close to resting or breeding places of Ae. aegypti in the houses. Entomological data collected during the period 1987 - 88 showed residual permethrin activity for about 1 to 2 months and population density of Ae. aegypti indoor was slightly decreased.