Four benzoylphenyl urea and one substituted melamine chitin synthesis inhibitors were evaluated for their potential to control German cockroaches, Blattella germanica (L.). Chitin synthesis inhibitors fed to adult German cockroaches as 0.25% baits during only the first othecal cycle resulted in a darkening of othecal coloration and reduced egg hatch. Effects persisted to the second othecal cycle even though the feeding of treated bait was discontinued. By the third othecal cycle, reproduction returned to normal. Exposure of nymphs to residues or feeding of 0.25%baits resulted in 100%nymphal mortality for the benzoylphenyl ureas CGA--112913 N-[[[3,5-dichloro-4-[[3-chlore-t-(trifluoromethyl)-2-pyridinyl] oxy])phenyl]amino]-carbonyl]-2,6-difluorobenzamide) and UC-84572. UC-84572 significantly reduced nymphal populations from 5-12 wk after treatment as a 0.25%bait. Sprays applied at 22.9 /Jog/cm2did not result in a high degree of control of German cockroach nymphs; however, an increased rate of 45.8 /Jog/cm2did provide reliable control. The chlorpyrifos standard did not significantly reduce nymphal populations until after 5 wk after treatment.