Place roach traps in problem areas, such as inside kitchen cabinets and near trash bins. Roach traps are typically either glue traps that capture the roaches or poison traps that kill the roaches with poisoned bait but do not contain them. Examples of these products include Springstar's Biocare Cockroach Trap and Raid's Roach Trap & Egg Stop.
Douse the roaches with roach pesticide spray. This option is best if you see a live roach running through an area. The pesticide works on contact, typically killing the bug within 10 minutes. Examples of these products include Raid and Bengal. For an organic alternative that doesn't depend on toxic chemicals, try a product like Kleen-Free's Insect Eliminator.
Mix your own roach-killing treatment at home for a more cost-effective method. Mix a cup of Borax, half a cup of white flour and a fourth of a cup of cocoa powder. Borax is a natural roach killer, while the cocoa attracts the bugs.
Sprinkle the powder wherever you have a roach problem. Roaches tend to congregate in dark areas near food sources. Lightly dust the powder in an even layer.
Remove the problems that are attracting roaches. Clean up trash, wipe food spills on counters and store food in sealed, airtight containers. Roaches multiply quickly and travel far. Killing roaches without fixing the original problem will simply cause a recurrence of infestation.