Question: How long after an exterminator visits and sprays/places traps/etc. should it take cockroaches to die off completely?

ANSWER  It could take several weeks or longer–depending on the size of the infestation and the type of treatment that was done.

You can also use baits for household cockroaches because they are more effective than aerosol sprays and liquid treatments.   Place them where you spotted the roaches.  Place plastic baits in cabinets, under sinks, and near appliance motors.  Apply gels in cracks and other places roaches have been seen.  Replace gels after they have been eaten by the cockroaches.  Bait is effective for many months.  It might take a few weeks for these procedures to work.

Related Questions:
The Orkin Man used the information above to also answer the following questions submitted by Orkin.com users.

Question: How many treatments does it typically take before you are “cockroach free”?

Question: How long does it take to get rid of German Cockroaches?