Several insecticides (including different active substances and formulations) were applied to sewer shafts to control Periplaneta americana (LINNAEUS, 1758) populations in Valencia (eastern Spain). Results show that the best products for cockroach control were the paints (with and without insecticide), which provided an optimal reduction of P. americana populations for up to three months (P < 0.001). Therefore, it is important to note that the reduction of cockroach populations as well as the persistence of the insecticide effect in sewers was similar in both types of paints. A product combining two pyrethroids (Tetramethrin and Alfacipermetrin) and piperonyl butoxide also gave excellent results with cockroach control during one month. Two organophosphate insecticides (Clorpyrifos and Diazinon) significantly reduced cockroaches for only one week. Finally, our work indicates that the Insect Growth Regulators (IGRs) we tested are not recommendable active substances for the control of P. americana in sewers.