BACKGROUND Cockroaches consists of 4000 species, of which 40 species are serious domestic pests. They have involved the mechanical transmission of various pathogenic viruses, bacteria, and protozoans to humans. This study aimed to determine different control methods of P. americana in sewage system of Esfahan City, central Iran using different insecticides recommended by WHO. METHODS Totally, 164 manholes with at least more than three cockroaches were selected until 2017 for this study. The species of cockroaches were identified; the adults and nymphs were counted and recorded. Each sewer shaft was assigned to one treatment method in an ascending order of number of cockroaches counted, coding the treatment method with paint on the lower part of the wall near the manhole cover. The manhole shafts were then inspected at 1 and 5 months' post-treatment. Data analyzed by statistical methods. RESULTS Almost all of the products (Excluding boric acid with bait formulation) resulted in appropriate control within one month of application. The appropriate products for chemical control of cockroaches were the chlorpyrifos 5% Emulsifiable Concentrate (EC), diazinon 5% (EC), diazinon 0.05% (EC) and cypermethrin 5% Fog. These pesticides achieved an optimal reduction of population providing more than 90% control of cockroaches for five consecutive months. CONCLUSIONS The emulsifiable concentrates and fog formulations in the control were more successful compared to other methods and this was penetration deep into the hiding places of cockroaches.